a. being in accord with established forms and conventions and requirements (as e.g. of formal dress)
s. characteristic of or befitting a person in authority
a. (of spoken and written language) adhering to traditional standards of correctness and without casual, contracted, and colloquial forms
s. logically deductive
a. 正式的, 形式的, 礼仪的, 拘于礼节的, 拘谨的
n. 正式的社交活动