v. & n.
v. 1 intr. not succeed (failed in persuading; failed to qualify; tried but failed). 2 a tr. & intr. be unsuccessful in (an examination, test, interview, etc.); be rejected as a candidate. b tr. (of a commodity etc.) not pass (a test of quality). c tr. reject (a candidate etc.); adjudge unsuccessful. 3 intr. be unable to; neglect to; choose not to (I fail to see the reason; he failed to appear). 4 tr. disappoint; let down; not serve when needed. 5 intr. (of supplies, crops, etc.) be or become lacking or insufficient. 6 intr. become weaker; cease functioning; break down (her health is failing; the engine has failed). 7 intr. a (of an enterprise) collapse; come to nothing. b become bankrupt.
n. a failure in an examination or test. fail-safe reverting to a safe condition in the event of a breakdown etc. without fail for certain, whatever happens.
[ ME f. OF faillir (v.), fail(l)e (n.) ult. f. L fallere deceive ]