S: (adj) formal (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"
S: (adj) formal (characteristic of or befitting a person in authority) "formal duties"; "an official banquet"
S: (adj) formal ((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"