1530s, "untimeliness," from Latin immaturitatem (nominative immaturitas) "unripeness," from immaturus "unripe, untimely" (see immature). Meaning "lack of maturity" attested from c. 1600.
Entries linking to immaturity
immature adj.
1540s, "untimely, premature," from Latin immaturus "untimely, unripe," from assimilated form of in- "not, opposite of" (see in- (1)) + maturus "ripe, timely, early" (see mature (v.)). In 16c., usually in reference to early death; main modern sense of "not fully developed" first recorded 1640s. In reference to mentalities or behaviors not considered age-appropriate, from 1920. Related: Immaturely.