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.
Having lost a component, an ingredient, or a faculty or a feature; rendered poor in something; depleted.
Reduced to poverty.