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.
consisting in the absence of something; negative
causing privation; depriving
indicating the absence of something
something that causes privation or indicates an absence