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.
Ideal but often impractical; visionary.
Of or pertaining to or resembling a utopia.
Someone who supports or heralds the establishment of a utopia.