alter

alter — verb

1. to make small changes to the way something looks, sounds, behaves, or works — or

1.verbtransitive / intransitiveB2
Definition

to make small changes to the way something looks, sounds, behaves, or works — or for that thing itself to shift in those ways — while its overall identity stays the same.

Example

Dilnoza altered the recipe by adding ginger and a little less sugar.

alter + noun (object) for tweaking a recipe

The new manager altered the office layout so quieter staff sat near the windows.

Common collocations
  • alter slightly
  • alter dramatically
  • alter the course of
  • alter someone's view
  • alter a recipe
  • alter the layout
Synonyms
  • change

    more general; can cover both small adjustments and full replacement

  • modify

    close to 'alter' but slightly more formal and often technical

  • adjust

    small, targeted tweaks aimed at a better fit or result

  • amend

    formal, mostly for written texts, laws, or agreements

Antonyms
  • preserve

    deliberately keep something exactly as it is

  • maintain

    keep the current state, without changing it

Grammar Patterns

alter + noun

alter + from X to Y

Usage Note

Suggests partial, often subtle adjustment — the thing keeps its core identity. Distinguish from sense 2 (specifically clothing) and from total replacement verbs like 'transform' or 'replace'.

Common Mistakes

The caterpillar altered into a butterfly.
The caterpillar changed into a butterfly.
'alter' implies the thing keeps its identity; full transformation needs 'change' or 'turn'.

2. to take in, let out, or resew a garment — for example a dress, suit, or pair of

2.verbtransitiveB2
Definition

to take in, let out, or resew a garment — for example a dress, suit, or pair of trousers — so that it sits well on the wearer's body.

Example

The tailor altered Mei's wedding dress to fit her after she lost weight.

typical subject: tailor / seamstress

Could you alter these trousers? The waist is a bit too loose.

Common collocations
  • alter a dress
  • alter a suit
  • alter the hem
  • have something altered
Synonyms
  • tailor

    specifically reshape clothing by sewing; emphasises a custom fit

  • take in

    informal phrasal verb for making clothing tighter or smaller

  • let out

    informal phrasal verb for making clothing looser or larger

Grammar Patterns

alter + clothing item

Usage Note

Object is almost always a piece of clothing (dress, suit, trousers, hem). Often appears in passive ('have something altered') because the wearer pays a tailor to do the work.

Common Mistakes

I altered my hair last weekend.
I had my hair restyled last weekend.
this sense applies to clothing, not hair, makeup, or appearance generally.

3. to perform a surgery on an animal — usually a cat or dog — that takes out its se

3.verbtransitiveC1
Definition

to perform a surgery on an animal — usually a cat or dog — that takes out its sex organs so it cannot breed; a gentler way of saying 'castrate' or 'spay'.

Example

The shelter altered every kitten before letting families take one home.

typical subject: shelter / vet / clinic

Dr. Otto recommended altering our puppy at six months old.

polite alternative to 'neuter' or 'spay'

Common collocations
  • alter a pet
  • have an animal altered
  • altered cat
  • altered dog
Synonyms
  • neuter

    general veterinary term for either sex; less euphemistic than 'alter'

  • spay

    specifically for female animals; remove the ovaries

  • castrate

    specifically for male animals; remove the testicles

  • fix

    informal American English for 'neuter' a pet

Grammar Patterns

alter + animal

Usage Note

Used as a softer, public-friendly alternative to 'neuter' or 'spay', especially in animal-shelter and pet-clinic notices. Object is an animal (often a pet), never a person.

Common Mistakes

The vet altered my cat's diet.
The vet changed my cat's diet.
in this veterinary sense, 'alter' specifically means the desexing surgery, not any other change.

Word family

  • alteration
    nounB2
  • alterable
    adjectiveC2
  • unalterable
    adjectiveC1
  • unaltered
    adjectiveC1
  • alternative
    nounB1
  • alternate
    verbC1

Synonym discussion

Sense: verb/1

All five verbs talk about making something different, but they pull in different directions. 'Change' is the broadest and most neutral — it covers everything from a tiny tweak to a full swap. 'Alter' sits one step narrower: it suggests partial, often subtle reshaping, while the underlying identity stays. 'Modify' overlaps with 'alter' but feels slightly more formal and often appears in technical or design contexts (modify a design, modify a contract). 'Adjust' is smaller still and focused on getting a better fit or result — you adjust a mirror, a setting, or a plan. 'Amend' is the most formal and usually applies to written things: laws, motions, contracts, drafts. Compare: she altered the dress (resewed it); she changed her dress (put on a different one); the senate amended the bill (voted in textual edits).

alter ↗change ↗modify ↗adjust ↗amend ↗

Common collocations

Nouns

Adverbs

Phrases

  • alter the course of history
  • alter beyond recognition
  • alter someone's view
  • have something altered

Prepositions

Etymology

LatinMedieval LatinOld FrenchMiddle EnglishEnglish

'Alter' came into late Middle English from Medieval Latin 'alterare' (to make different), which itself was built on the Latin 'alter' meaning 'the other (of two)'. The same root sits behind 'alternative' and 'alternate'. The animal-surgery sense developed much later in American English, as a polite, public-facing way to talk about neutering pets without using 'castrate' or 'spay' directly.