indiscreet adj.

word-forming element meaning "not, opposite of, without" (also im-, il-, ir- by assimilation of -n- with following consonant, a tendency which began in later Latin), from Latin in- "not," cognate with Greek an-, Old English un-, all from PIE root *ne- "not."

In Old French and Middle English often en-, but most of these forms have not survived in Modern English, and the few that do (enemy, for instance) no longer are felt as negative. The rule of thumb in English has been to use in- with obviously Latin elements, un- with native or nativized ones.

"perceive or recognize the difference or distinction between (two or more things);" also "distinguish (an object) with the eyes, see distinctly, behold;" also "perceive rationally, understand;" late 14c., from Old French discerner (13c.) "distinguish (between), separate" (by sifting), and directly from Latin discernere "to separate, set apart, divide, distribute; distinguish, perceive," from dis- "off, away" (see dis-) + cernere "distinguish, separate, sift" (from PIE root *krei- "to sieve," thus "discriminate, distinguish"). Related: Discerned; discerning.

"not containing distinct parts," 1782 (earlier "not distinctly separate," c. 1600), from Latin indiscretus "unseparated; indistinguishable, not known apart," from in- "not, opposite of" (see in- (1)) + discretus "separated, distinct" (in Medieval Latin "discerning, careful"), past participle of discernere "distinguish" (see discern). Related: Indiscretely; indiscreteness.