Insufficient or inadequate in amount.
Lacking something essential; often construed with in.
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.
Excessive; going beyond that what is natural or sufficient.
That which ought not to be done; illegal; unjustified.
Not owing or payable.