immarcescible 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.

"withering, liable to decay, ephemeral," 1727, from Latin marcescentem (nominative marcescens), present participle of marcescere "to wither, languish, droop, decay, pine away," inchoative of marcere "to wither, droop, be faint," from Proto-Italic *mark-e-, from PIE root *merk- "to decay" (source also of Sanskrit marka- "destruction, death;" Avestan mareka- "ruin;" Lithuanian mirkti "become weak," merkti "to soak;" Ukrainian dialect morokva "quagmire, swamp," Middle High German meren "dip bread into water or wine," perhaps also Middle Irish mraich, Welsh brag "a sprouting out; malt").