A person who is deficient.
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).
Similarly producing results or performing deeds in abundance
Fertile; producing offspring or fruit in abundance — applied to plants producing fruit, animals producing young, etc.
Of a flower: from which another flower is produced.