wanting
adjective
1 when they came under siege the defences were found wanting:
deficient, inadequate, lacking, insufficient, imperfect, not up to standard/par, not good enough, disappointing, unsatisfying, unacceptable, not acceptable, not up to expectations, leaving much to be desired, flawed, faulty, defective, impaired, unsound, substandard, inferior, second-rate, poor, shabby, shoddy, patchy, sketchy, limited, restricted, incomplete, unfinished, unpolished, unrefined;
British, informal not much cop.
▷antonyms sufficient, acceptable.
wanting Oxford Dictionary of English