| Adj. | 1. | deficient - inadequate in amount or degree; "a deficient education"; "deficient in common sense"; "lacking in stamina"; "tested and found wanting" inadequate, unequal - lacking the requisite qualities or resources to meet a task; "inadequate training"; "the staff was inadequate"; "she was unequal to the task" |
| 2. | deficient - of a quantity not able to fulfill a need or requirement; "insufficient funds" | |
| 3. | deficient - falling short of some prescribed norm; "substandard housing" nonstandard - varying from or not adhering to a standard; "nonstandard windows"; "envelopes of nonstandard sizes"; "nonstandard lengths of board" |