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.
Small (especially contemptibly small) in amount.
Particularly of pigs or pork: infected with larval tapeworms or trichinae (parasitic roundworms).
Of a person: infected with measles.