formal

(noun) a lavish dance requiring formal attire. Synonyms: ball.

(noun) a gown for evening wear. Synonyms: dinner dress, dinner gown, evening gown.

(adj) being in accord with established forms and conventions and requirements (as e.g. of formal dress). Synonyms: formal (vs. informal). Examples: "Pay one's formal respects." "Formal dress." "A formal ball." "The requirement was only formal and often ignored." "A formal education."

(adj) characteristic of or befitting a person in authority. Examples: "Formal duties." "An official banquet."

(adj) (of spoken and written language) adhering to traditional standards of correctness and without casual, contracted, and colloquial forms. Synonyms: formal (vs. informal). Example: "The paper was written in formal english."

(adj) represented in simplified or symbolic form. Synonyms: conventional, schematic.

(adj) logically deductive. Example: "Formal proof."

(adj) refined or imposing in manner or appearance; befitting a royal court. Synonyms: courtly, stately. Example: "A courtly gentleman."