Not sufficient; of a type or kind that does not suffice, that does not satisfy requirements or needs. / Not sufficient; lacking competent power or ability; unqualified, unequal, unfit.

An inadequate quantity of; not enough. / (as pronoun) A quantity (of something) that is less than is needed.

not sufficiently

The lack of sufficiency; a shortage or inadequacy.

Obsolete form of insufficiency.

plural of insufficiency

Synonym of principle of indifference