for·mal / ˈfôrməl/ • adj. 1. done in accordance with rules of convention or etiquette; suitable for or constituting an official or important situation or occasion: a formal dinner party. ∎  (of a person or their manner) prim or stiff. ∎  of or denoting a style of writing or public speaking characterized by more elaborate grammatical structures and more conservative and technical vocabulary. ∎  (esp. of a house or garden) arranged in a regular, classical, and symmetrical manner.2. officially sanctioned or recognized: a formal complaint. ∎  having a conventionally recognized form, structure, or set of rules: he had little formal education.3. of or concerned with outward form or appearance, esp. as distinct from content or matter: I don't know enough about art to appreciate the purely formal qualities. ∎  having the form or appearance without the spirit: his sacrifice will be more formal than real. ∎  of or relating to linguistic or logical form as opposed to function or meaning.• n. an evening gown. ∎  an occasion on which evening dress is worn.

formal The name of a stratigraphic unit or taxon is formal when it has been established according to the conventional principles of nomenclature and is being used in the sense of a proper name, e.g. Barremian Stage, Osteichthyes (bony fish). In formal use the initial letter is capitalized. Compare INFORMAL.

FORMAL. A term concerned with: (1) Structure and order: a formal education, formal grammar. (2) More or less elevated and stylized ceremonial: a formal dinner, formal and informal meetings. (3) Style and usage of a relatively elevated and impersonal kind: a highly formal writing style; ‘receive’ a more formal word than ‘get’.