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.
Minuscule.
A wiener, a hot dog.
A penis, from the resemblance to a wiener, sometimes thought of as small by influence from teeny weeny