informal adj

1 not formal; "conservative people unaccustomed to informal dress"; "an informal free-and-easy manner"; "an informal gathering of friends" [ant: formal]

2 not officially recognized or controlled; "an informal agreement"; "a loose organization of the local farmers" [syn: loose]

3 used of spoken and written language [ant: formal]

4 having or fostering a warm or friendly atmosphere; especially through smallness and informality; "had a cozy chat"; "a relaxed informal manner"; "an intimate cocktail lounge"; "the small room was cozy and intimate" [syn: cozy, intimate]

English

Pronunciation

• Rhymes with: -ɔː(r)məl

Adjective

1. Not formal or ceremonious; casual.

   an informal get-together

2. Not in accord with the usual regulations; unofficial.

   an informal agreement

3. Suited for everyday use.

   informal clothes

4. In the context of "of language": Reflecting everyday, non-ceremonious usage.

Translations

See also

• colloquial
• slang

The term formal has a number of uses, including:

General

• relating to formality
• opposite of informal

Social

• Formal occasion
  • Formal attire worn on such occasions
  • Formals are particular meals at some British universities
  • In Australian or British English, a "formal" is the equivalent of the American prom dance.
  • In American English, a "formal" is organized by a college or university organization, typically but not always a fraternity or sorority.
• Informal occasion (included as Informal redirect here); see Dress code (Western) for the distinctions between Formal, Semi-formal, and Informal
  • Informal attire (not to be confused with Casual -- see Dress code (Western))

Philosophical

• relating to form, i.e. appearance rather than essence.
  • relating to Formalism, i.e. emphasis on form over content or meaning.
• formal logic logical argument based only on the form and not on the meaning.
• Formal cause, Aristotle's intrinsic, determining cause.

Mathematics

• formal power series, a generalization of power series without requiring convergence, used in combinatorics;
• formal calculation, a calculation which is systematic, but without a rigorous justification;
• formal set theory as opposed to naive set theory;
• formal derivative, an operation on elements of a polynomial ring which mimics the form of the derivative from calculus.

Logic and Language

• formal system, an abstract means of generating inferences in a formal language;
  • formal language, comprising the symbolic "words" or "sentences" of a formal system;
    • formal grammar, a grammar describing a formal language;
  • formal proof, a fully rigorous proof as is possible only in a formal system.

Computer science

• formal methods in computer science, including:
  • formal specification describes what a system should do, not how it should do it
  • formal verification proves correctness of a system

See also the Language section of Mathematics, above

Linguistic

• Formal equivalence word-for-word translation (especially of the Bible)

See also the Language section of Mathematics, above

Chemical

• A unit of concentration
• short or prefix form for formalin
• short or prefix form for formaldehyde
• synonym for dimethoxymethane

See also

• Informal economy

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