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.
"disentangle, disengage, set free," 1610s, from Latin extricatus, past participle of extricare "disentangle," figuratively "clear up, unravel," perhaps from ex "out of" (see ex-) + tricae (plural) "perplexities, hindrances," which is of unknown origin. Related: Extricated; extricating.
<a href="https://www.etymonline.com/word/inextricable">Etymology of inextricable by etymonline</a>
Harper, D. (n.d.). Etymology of inextricable. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/inextricable