phase

verb

phased; phasing

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 in

phase in new models

Did you know?

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

Recent Examples on the Web

The company adds that any funding would be phased over time, and that the other party is not obligated to proceed. —Malana Vantyler, USA Today, 3 June 2026

If public speaking does not phase you, get on stage. —Jodie Cook, Forbes.com, 30 May 2026

The looming threat of a Chinese robotics domination didn’t seem to phase Osaka University Professor Hiroshi Ishiguro, who has worked on humanoids for decades, including one that’s his clone. —ABC News, 28 May 2026

The service plans to phase replacements through future task orders instead of replacing the entire network at once. —Aamir Khollam, Interesting Engineering, 20 May 2026

Word History

First Known Use

1904, in the meaning defined at sense 1

Phrases Containing phase

• color phase
• in phase
• L-phase
• M phase
• out of phase
• phase-contrast
• phase-contrast microscope
• phase down
• phase in
• phase modulation
• phase out
• single-phase
• S phase
• sub-phase
• three-phase
• two-phase

Rhymes for phase

• baize
• bays
• blase
• blaze
• braes
• braze
• chaise
• claes
• clays
• craze
• dais
• days

Kids Definition

phase

1 of 2 noun

ˈfāz 

1

: a particular appearance or state in a repeating series of changes

phases of the moon

2

: a step or part in a series of events or actions : stage

3

: a particular part or feature (as of an activity, situation, or a subject being considered) : aspect

4

: a physically different portion or kind of matter present in a mixed system

the three phases ice, water, and steam

phase

2 of 2 verb

phased; phasing

1

: to do in steps according to a plan

2

: to introduce in stages

—usually used with in

phase in new models

Medical Definition

phase

noun

ˈfāz 

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