Lacking something essential; often construed with in.
Insufficient or inadequate in amount.
Of a number n, Having the sum of divisors σ(n)<2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n).
A person who is deficient.
Destitute of shifts or expedients; lacking proper means.
Untrustworthy as a result of being incompetent at the job.
Lazy, unmotivated.