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).
an impotent or powerless person
a man who has erectile dysfunction
lacking physical strength or vigor; weak
incapable of sexual intercourse, often because of an inability to achieve or sustain an erection, having impotentia coeundi
lacking in power, as to act effectively; helpless
sterile