\ ˈfāz How to pronounce phase (audio) \

Definition of phase

 (Entry 1 of 2)

1 : a particular appearance or state in a regularly recurring cycle of changes phases of the moon
2a : a distinguishable part in a course, development, or cycle the early phases of her career
b : an aspect or part (as of a problem) under consideration
3 : the point or stage in a period of uniform circular motion, harmonic motion, or the periodic changes of any magnitude varying according to a simple harmonic law to which the rotation, oscillation, or variation has advanced from its standard position or assumed instant of starting
4 : a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physicochemical system
5 : an individual or subgroup distinguishably different in appearance or behavior from the norm of the group to which it belongs also : the distinguishing peculiarity
in phase
: in a synchronized or correlated manner
out of phase
: in an unsynchronized manner : not in correlation


phased; phasing

Definition of phase (Entry 2 of 2)

transitive verb

1 : to adjust so as to be in a synchronized condition
2 : to conduct or carry out by planned phases
3 : to introduce in stages usually used with inphase in new models

Keep scrolling for more

Other Words from phase


phasic \ ˈfā-​zik How to pronounce phasic (audio) \ adjective

Synonyms for phase

Synonyms: Noun

Visit the Thesaurus for More 

Phase and Faze

Phase and faze are homophones (words pronounced alike but different in meaning, derivation, or spelling) that may easily be confused. Despite the similarity in pronunciation, these words bear little semantic resemblance to one another.

Although phase can function as a verb – it is found especially in combinations such as phase out, phase in, and phase into, meaning “to end, begin, etc. in phases” – the word is most commonly encountered as a noun, in which it typically carries a meaning related to steps in a process, cycles, or stages of development (as in “phases of the moon”).

Faze is generally used only as a verb, and means “to daunt or disconcert.” It often appears in negative expressions such as “it didn’t faze her a bit” or “nothing fazes him.”

Examples of phase in a Sentence

Noun The project will be done in three phases. He's in the final phase of treatment now. The building project marks a new phase in the town's development. He has been throwing tantrums a lot, but the doctor says it's just a phase. a calendar based on the phases of the moon
See More
Recent Examples on the Web: Noun UConn’s defense: The Huskies have been outstanding in every phase of defense since the first half of the St. Joseph’s game on Nov. 13. Dom Amore,, "UConn men’s basketball vs. No. 18 Xavier: time, how to watch, broadcasters, preview," 22 Nov. 2019 Hairs in the telogen phase generally fall out 100 days later, which means that people would see a shedding at the end of the summer and into the fall. Allure, "Why Your Hair Sheds More in Fall and What You Can Do About It," 21 Nov. 2019 Work is underway on the once-industrial parcel along East Cromwell Street to build the $500 million first phase that will include 1.1 million square feet of offices, apartments, shops and parks. Lorraine Mirabella,, "Port Covington developer will move offices to waterfront project," 20 Nov. 2019 It was largely completed this summer, with Cobalt planning to build one more phase. Tom Daykin, Milwaukee Journal Sentinel, "84 South stores in Greenfield sell for $34.5 million. Developer to use cash for other Milwaukee-area projects.," 18 Nov. 2019 Well, let’s just say Mr. Sharpe likely never went through an awkward phase. Jasmine Grant, Essence, "Shannon Sharpe's Throwback Photo Proves He's Been Fine His Whole Life," 15 Nov. 2019 Researchers at Brown University have found that Cooper pairs of electrons can model three total phases of matter—and the third is new. Caroline Delbert, Popular Mechanics, "This Is an Entirely New State of Matter," 15 Nov. 2019 Friday, November 8, 2019, marked the last phase of a long journey for Juliana Lamar. Rebecca Angel Baer, Southern Living, "Tennessee Judge Holds Baby on His Hip as Mom Takes Oath of Office," 14 Nov. 2019 The Denver City Council is set to consider $136 million in new contracts Monday night, while another large contract is expected in January for Hensel Phelps, the new lead construction contractor that DIA selected to finish the project’s first phase. Jon Murray, The Denver Post, "Fired Denver airport contractors’ claims raise questions about oversight as massive project restarts," 14 Nov. 2019 Recent Examples on the Web: Verb When the spending is fully phased in, Baltimore County, for example, would need to add $88 million to its annual education funding, while Anne Arundel would have to put in another $98 million. Talia Richman,, "Baltimore mayor tells agencies to anticipate cuts as city prepares to fund statewide plan to improve schools," 22 Nov. 2019 In other words, the FDA could allow companies to sell e-cigarettes as the agency phased in manufacturing standards, restrictions on flavors, and other standards. Joshua M. Sharfstein, STAT, "Why the FDA was unable to prevent a crisis of vaping among kids," 21 Nov. 2019 In 2007, for example, lawmakers raised the age of juvenile jurisdiction to 18, creating a five-year plan for phasing 16- and 17-year olds into the juvenile justice system. Kelan Lyons,, "Officials consider new state agency to deal with minors in criminal justice system," 18 Nov. 2019 Service has resumed and shuttle buses are being phased out,’’ the tweet reads., "Green Line’s Riverside line is back and shuttle buses are being phased out, T says - The Boston Globe," 1 Nov. 2019 That hole is expected to grow by roughly $10 million for at least the next three years, as pension rate adjustments are phased in by 12%. Darcy Costello, The Courier-Journal, "Some library services are coming back to Fern Creek. Here's what to know," 29 Oct. 2019 Democratic candidates have put forth a number of ambitious proposals to tackle climate change that calls for dramatically phasing back fossil fuel production in the United States and building out green infrastructure and manufacturing. Ella Nilsen, Vox, "Harry Reid wants to kill the Senate filibuster to solve climate change," 8 Aug. 2019 In May, California’s EPA issued new rules to phase the chemical out statewide. Paul Rogers, The Mercury News, "How California has blocked Trump’s environmental rollbacks," 27 July 2019 Stimpson, during the meeting, said his administration offered a few years ago to shrink the size of the police jurisdiction by 1-1/2 miles through a phased-in approach with the Mobile County Sheriff’s Office, which would take on the extra residents. al, "Amid annexation talks, Mobile considers cutting police jurisdiction services," 5 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'phase.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of phase


1647, in the meaning defined at sense 1


1904, in the meaning defined at sense 1

History and Etymology for phase


New Latin phasis, from Greek, appearance of a star, phase of the moon, from phainein to show (middle voice, to appear) — more at fancy

Keep scrolling for more

Learn More about phase

Time Traveler for phase

Time Traveler

The first known use of phase was in 1647

See more words from the same year

Statistics for phase

Last Updated

27 Nov 2019

Cite this Entry

“Phase.” The Dictionary, Merriam-Webster Inc., Accessed 5 December 2019.

Keep scrolling for more

More Definitions for phase


How to pronounce phase (audio)

English Language Learners Definition of phase

: a part or step in a process : one part in a series of related events or actions
: a short period of time during which a person behaves in a particular way or likes a particular thing
: the shape of the part of the moon that is visible at different times during a month


\ ˈfāz How to pronounce phase (audio) \

Kids Definition of phase

1 : a step or part in a series of events or actions : stage I have completed the first phase of my training.
2 : the way that the moon or a planet looks to the eye at any time in its series of changes with respect to how it shines The new moon and the full moon are two phases of the moon.


\ ˈfāz How to pronounce phase (audio) \

Medical Definition of phase

1 : a particular appearance or state in a regularly recurring cycle of changes
2 : a distinguishable part in a course, development, or cycle the early phases of a disease
3 : a point or stage in the period of a periodic motion or process (as a light wave or a vibration) in relation to an arbitrary reference or starting point in the period
4 : a homogeneous, physically distinct, and mechanically separable portion of matter present in a nonhomogeneous physicochemical system especially : one of the fundamental states of matter usually considered to include the solid, liquid, and gaseous forms
5 : an individual or subgroup distinguishably different in appearance or behavior from the norm of the group to which it belongs also : the distinguishing peculiarity

Keep scrolling for more

Comments on phase

What made you want to look up phase? Please tell us where you read or heard it (including the quote, if possible).


to accept, comply, or submit

Get Word of the Day daily email!

Test Your Vocabulary

Semantic Drift Quiz

  • a twisty river
  • Which of the following was once a synonym for fun?
Spell It

Can you spell these 10 commonly misspelled words?

Syn City

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!