instinct (n.)

Middle English stiken, from Old English stician "to pierce or puncture, to stab with a weapon; transfix; goad," also "to remain embedded, stay fixed, be fastened," from Proto-Germanic *stekanan "pierce, prick, be sharp" (source also of Old Saxon stekan, Old Frisian steka, Dutch stecken, Old High German stehhan, German stechen "to stab, prick").

This is reconstructed to be from PIE *steig- "to stick; pointed" (source also of Latin instigare "to goad," instinguere "to incite, impel;" Greek stizein "to prick, puncture," stigma "mark made by a pointed instrument;" Old Persian tigra- "sharp, pointed;" Avestan tighri- "arrow;" Lithuanian stingu, stigti "to remain in place;" Russian stegati "to quilt").

Etymologists have tried to connect this to *stegh-, reconstructed PIE root of words for sting, but Boutkan (2005) writes that the attempt has "formal problems" and the relationship "remains unclear."

Loosely, "put something where it will remain," with or without the notion of penetration. Hence the figurative sense of "remain permanently in mind" (c. 1300). The meaning "persist (in a course of action), insist upon" is mid-15c. The transitive sense of "to fasten (something) in place" is attested from late 13c. Related: Stuck; sticking.

To stick out "protrude, project" is recorded from 1560s. Slang stick around "remain" is from 1912; stick it as a rude item of advice is recorded by 1922. Sticking point, beyond which one refuses to go, is from 1956. Sticking-place, where any thing put will stay, is from 1570s; modern use generally is an echo of Shakespeare.

1640s, from Latin instinct-, past participle stem of instinguere "to incite, impel" (see instinct) + -ive. Related: Instinctively (1610s); instinctiveness. Coleridge uses instinctivity.