Is it ensure, insure, or assure?
1520s, from Late Latin insufficientia, noun of quality from insufficientem (see insufficient). Insufficience "deficiency" is from early 15c.
insufficiency in·suf·fi·cien·cy (ĭn'sə-fĭsh'ən-sē)n.
An inability of a bodily part or an organ to function normally.
A moral or mental incompetence.
An inadequate supply.