alter

verb

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

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
alterability noun
alterable adjective
alterably adverb
alterer 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
These keys are highly resistant to interception because any attempt to eavesdrop on a quantum key transmission will alter the data, alerting both parties to the presence of an intruder. John Prisco, Forbes, 12 Dec. 2024 The way bots respond to negative content will also be altered for teen users, Character. Kerry Breen, CBS News, 12 Dec. 2024 But Trump's new administration could alter these trends. Gordon G. Chang, Newsweek, 11 Dec. 2024 The man, who filed his lawsuit as a John Doe in October, had his face concealed and his voice altered to maintain his anonymity. Cheyenne Roundtree, Rolling Stone, 11 Dec. 2024 See all Example Sentences for alter 

Word History

Etymology

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

First Known Use

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

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

Dictionary Entries Near alter

Cite this Entry

“Alter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alter. Accessed 24 Dec. 2024.

Kids Definition

alter

verb
al·​ter ˈȯl-tər How to pronounce alter (audio)
1
: to change partly but usually not completely
alter a dress
2
alterability noun
alterable adjective
alterer noun
Etymology

Middle English alteren "to make different," from Latin alterare (same meaning), from Latin alter "other (of two)" — related to adulterate

Medical Definition

alter

1 of 2 transitive verb
al·​ter
ˈȯl-tər
altered; altering
-t(ə-)riŋ

alter

2 of 2 noun
: one of the distinct identities or personality states manifested in an individual with dissociative identity disorder

More from Merriam-Webster on alter

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