Synonyms of informal

informal

adjective

(ˌ)in-ˈfȯr-məl 

1

as in unconventional

not rigidly following established form, custom, or rules

an informal meeting allowed everyone to get acquainted

Synonyms & Similar Words

• unconventional
• unofficial
• unorthodox
• irregular
• casual
• unceremonious
• heterodox
• unauthorized
• relaxed
• easygoing
• familiar
• offhand
• free and easy
• lax
• ultracasual
• loose

Antonyms & Near Antonyms

• formal
• regular
• conventional
• routine
• ceremonial
• orthodox
• proper
• correct
• ceremonious
• rigid
• decorous
• stiff
• restrained
• stuffy
• inhibited
• constrained
• uptight

2

as in casual

not designed to be worn only on special occasions

chose an informal flowery dress

Synonyms & Similar Words

• casual
• everyday
• relaxed
• workaday
• sporty
• slovenly
• sloppy
• dégagé
• shabby
• unkempt
• dressed down

Antonyms & Near Antonyms

• formal
• best
• dressy
• Sunday
• elegant
• fashionable
• stylish
• noncasual
• chic
• smart
• neat
• tidy
• trim
• dressed up
• semiformal

3

as in colloquial

used in or suitable for speech and not formal writing

the use of informal language in a scholarly article is really inappropriate

Synonyms & Similar Words

• colloquial
• vernacular
• nonformal
• conversational
• vulgar
• nonliterary
• dialectical
• unliterary
• dialectal
• slang
• unbookish
• regional
• nonstandard
• incorrect
• uneducated
• ungrammatical
• substandard
• slangy
• unlearned
• nongrammatical

Antonyms & Near Antonyms

• formal
• literary
• learned
• standard
• bookish
• proper
• correct
• grammatical
• educated
• genteel
• undialectical

Example Sentences

Recent Examples of informal

In June, 12 people were killed in an informal settlement in a Johannesburg suburb. — Nimi Princewill, CNN Money, 23 Sep. 2026

Harvin, who also lived in Washington Heights, had been accompanying Billini on her walks with Zeus for the two or three weeks before the killings as an informal bodyguard, according to friends and family. — Leonard Greene, New York Daily News, 23 Sep. 2026

On Friday and Saturday nights, live country and honky-tonk bands get couples two-stepping across the wooden dance floor, while most afternoons bring informal pickers’ circles where musicians gather for backyard jam sessions. — Alexandra Emanuelli, Southern Living, 23 Sep. 2026

What’s more, the two women leading the informal balloting are from Latin America. — The Monitor's Editorial Board, Christian Science Monitor, 22 Sep. 2026