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.
Done or occurring often; common.
Occurring at short intervals.
Addicted to any course of conduct; inclined to indulge in any practice; habitual; persistent.
To visit often.