formal

The word “formal” means following official or established rules and conventions. In plain terms, official, proper, or done according to set rules — the opposite of casual or informal.

“Formal” is pronounced FAW-muhl (/ˈfɔɹməl/ in IPA).

Here is “formal” used in a sentence: “The company sent a formal letter announcing the merger.”

The opposite of “formal” — its antonyms — is informal.

“Formal” is an adjective.

The word “formal” comes from Latin. From Old French formel, from Latin fōrmālis, from fōrma ("form").

“Formal” is a fairly common word in modern English, usually learned at around the B1 level.

“Formal” has 2 distinct senses listed in this dictionary. The most common is: following official or established rules and conventions.

Formal means following official rules and conventions, so it suits serious settings like ceremonies, business, or academic writing. Informal is casual and relaxed, the way you speak with friends. A formal email uses full sentences and polite structure; an informal one may use slang, contractions, and a friendly tone.

A wedding invitation, a job interview, and a business letter are all formal because they follow expected conventions. Formal clothing such as a suit or gown fits this idea too. In each case, established rules of dress, language, or behavior are being carefully observed rather than relaxed.

Neither; formal is neutral and its value depends on the situation. In a courtroom or official ceremony, being formal shows respect and seriousness. At a casual gathering, the same formality can feel stiff or distant. The key is matching your level of formality to what the setting calls for.

The main opposite is informal, meaning casual and relaxed. Related opposites include casual, relaxed, and colloquial, which describe everyday language or behavior that ignores strict rules. Where formal follows established conventions, these words describe a looser, friendlier, more spontaneous style.