Formal
WordNet
adjective
(1) Refined or imposing in manner or appearance; befitting a royal court
"A courtly gentleman"
(2) Being in accord with established forms and conventions and requirements (as e.g. of formal dress)
"Pay one's formal respects"
"Formal dress"
"A formal ball"
"The requirement was only formal and often ignored"
"A formal education"
(3) (of spoken and written language) adhering to traditional standards of correctness and without casual, contracted, and colloquial forms
"The paper was written in formal English"
(4) Logically deductive
"Formal proof"
(5) Characteristic of or befitting a person in authority
"Formal duties"
"An official banquet"
(6) Represented in simplified or symbolic form
noun
(7) A gown for evening wear
(8) A lavish dance requiring formal attire