informal
1 antonyms and opposites of informal, grouped by meaning.
Adj — Relaxed and casual rather than official or ceremonious.
Antonyms
How to use informal
The word patterns that sound natural to a native speaker.
Etymology
From in- ("not") plus formal.
Full origin of informal →Frequently asked questions
What does “informal” mean?
The word “informal” means relaxed and casual rather than official or ceremonious. In plain terms, casual rather than official or by-the-book.
How do you pronounce “informal”?
“Informal” is pronounced ihn-FAW-ml (/ɪnˈfɔɹ.m(ə)l/ in IPA).
How do you use “informal” in a sentence?
Here is “informal” used in a sentence: “It was an informal gathering, just close friends and family.”
What is another word for “informal”?
Words with a similar meaning to “informal” include not formal, ceremonious, not in accord with the usual regulations and suited for everyday use.
What is the opposite of “informal”?
The opposite of “informal” — its antonyms — is formal.
What part of speech is “informal”?
“Informal” is an adjective.
Is “informal” a common word?
“Informal” is a fairly common word in modern English, usually learned at around the B2 level.
What is the difference between informal and casual?
Both describe a relaxed, unofficial style and overlap heavily. Casual tends to emphasize an easygoing, low-effort manner or dress, while informal more broadly means not bound by official rules or ceremony, and is common when describing language, meetings, and writing.
What is the difference between informal and formal language?
Informal language is relaxed and conversational, using contractions, slang, and simple sentences, as in everyday speech and texts. Formal language avoids these, favoring precise vocabulary and complete structures, and suits official, academic, or professional settings.
When should you use informal instead of formal writing?
Use informal writing for personal messages, texts, casual emails, and friendly contexts where a relaxed tone suits the reader. Choose formal writing for official documents, academic work, and situations that call for professionalism and distance.
What is the difference between informal and unofficial?
Informal describes a relaxed, casual manner or tone, while unofficial means not authorized or not part of the official record. A meeting can be informal yet still official, or official in tone yet unofficial in status.