Unsuccessful
来自Big Physics
mid 17th century (originally as failer, in the senses ‘non-occurrence’ and ‘cessation of supply’): from Anglo-Norman French failer for Old French faillir (see fail).
wiktionary
un- + successful
etymonline
unsuccessful (adj.)
1610s, from un- (1) "not" + successful (adj.). Related: Unsuccessfully. A noun unsuccess "lack of success" is recorded from 1580s.
