al·​ter | \ ˈȯl-tər How to pronounce alter (audio) \
altered; altering\ ˈȯl-​t(ə-​)riŋ How to pronounce alter (audio) \

Definition of alter

transitive verb

1 : to make different without changing into something else an event that altered the course of history
2 : castrate, spay had the puppies altered

intransitive verb

: to become different customs that alter with the times

Other Words from alter

alterability \ ˌȯl-​t(ə-​)rə-​ˈbi-​lə-​tē How to pronounce alter (audio) \ noun
alterable \ ˈȯl-​t(ə-​)rə-​bəl How to pronounce alter (audio) \ adjective
alterably \ ˈȯl-​t(ə-​)rə-​blē How to pronounce alter (audio) \ adverb
alterer \ ˈȯl-​tər-​ər How to pronounce alter (audio) \ noun

Choose the Right Synonym for alter

change, alter, vary, modify mean to make or become different. change implies making either an essential difference often amounting to a loss of original identity or a substitution of one thing for another. changed the shirt for a larger size alter implies a difference in some particular respect without suggesting loss of identity. slightly altered the original design vary stresses a breaking away from sameness, duplication, or exact repetition. vary your daily routine modify suggests a difference that limits, restricts, or adapts to a new purpose. modified the building for use by the disabled

Examples of alter in a Sentence

Alcohol can alter a person's mood. He altered his will to leave everything to his sister. This one small event altered the course of history. The place has altered in the 10 years since I left. I'll need to have the dress altered before the wedding.
Recent Examples on the Web Life-threatening storm surge of up to 12 to 16 feet and catastrophic winds near where Ian makes landfall Wednesday could alter life in southwest Florida for weeks to come. NBC News, 28 Sep. 2022 If true, that would demonstrate that a collision with a probe can alter an asteroid’s trajectory. WIRED, 27 Sep. 2022 So my aim is to reset our assessment of what got us here, with the hope that a clearer perspective can help alter where we’re headed. Scott Galloway, Time, 27 Sep. 2022 That would prompt lawmakers to draft legislation that could neutralize SITLA’s independence and alter its mission, according to Schultz. Brian Maffly, The Salt Lake Tribune, 26 Sep. 2022 The Double Asteroid Redirect Test, or DART, will smash a spacecraft into a small asteroid called Dimorphos at 7:14 pm EDT in the expectation that the impact will alter Dimorphos' orbit around the nearby large asteroid Didymos. John Timmer, Ars Technica, 26 Sep. 2022 If all goes to plan, the collision will redirect the space rock and alter its flight path. Max Zahn, ABC News, 26 Sep. 2022 This is Chrysler’s offering to consumers to adjust the ability to customize certain categories of vehicle settings or to adjust and alter the driving experience for the vehicle. Marc Grasso, Hartford Courant, 24 Sep. 2022 Evan Flood discussed how Graham Mertz can alter the narrative of his career on Saturday night. Tim Bielik, cleveland, 24 Sep. 2022 See More

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

First Known Use of alter

14th century, in the meaning defined at transitive sense 1

History and Etymology for alter

Middle English alteren "to change, transform," borrowed from Anglo-French & Late Latin; Anglo-French alterer, borrowed from Late Latin alterāre, verbal derivative of Latin alter "second, another, next," derivative, with the suffix of opposition -ter-, from the base of alius "other" — more at else entry 1

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Time Traveler for alter

Time Traveler

The first known use of alter was in the 14th century

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Last Updated

7 Oct 2022

Cite this Entry

“Alter.” Dictionary, Merriam-Webster, Accessed 7 Oct. 2022.

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More Definitions for alter


al·​ter | \ ˈȯl-tər How to pronounce alter (audio) \
altered; altering

Kids Definition of alter

: to change partly but not completely … each time he had altered his course.— Walter Farley, The Black Stallion


transitive verb
al·​ter | \ ˈȯl-tər \
altered; altering\ -​t(ə-​)riŋ \

Medical Definition of alter

 (Entry 1 of 2)



Medical Definition of alter (Entry 2 of 2)

: one of the distinct identities or personality states manifested in an individual with dissociative identity disorder

More from Merriam-Webster on alter

Nglish: Translation of alter for Spanish Speakers

Britannica English: Translation of alter for Arabic Speakers


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