充要条件 chōngyàotiáojiàn necessary and sufficient condition Origin Definitions Defs Strokes Stroke Words Sentences Sents 充 chōng adjectiveadverb full (bound form) sufficient; full; ample要 yào adjective important (bound form) important; essential; vital; key条件 條件 tiáojiàn noun condition; circumstances a factor, circumstance, or state that influences how something exists or develops, such as living conditions or a current situation