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.
Trivial, or of little importance.
Of suspicious character, typically secretive or deceitful; shady.
Idle or frivolous.
The act of one who trifles; frivolous behaviour.