stimulus n.

Old English stician "to pierce, stab, transfix, goad," also "to remain embedded, stay fixed, be fastened," from Proto-Germanic *stik- "pierce, prick, be sharp" (source also of Old Saxon stekan, Old Frisian steka, Dutch stecken, Old High German stehhan, German stechen "to stab, prick"), 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").

Figurative sense of "to remain permanently in mind" is attested from c. 1300. Transitive sense of "to fasten (something) in place" is attested from late 13c. To stick out "project" is recorded from 1560s. Slang stick around "remain" is from 1912; stick it as a rude item of advice is first recorded 1922. Related: Stuck; sticking. 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.

Middle English prikke, "pointed object, something that punctures or stabs; sting of an insect; a goad; a pin or fastener; a pricking as a bodily pain or torment," from Old English prica (n.) "sharp point, puncture; minute mark made by sticking or piercing; particle, very small portion of space or time," a common Low German word (compare Low German prik "point," Middle Dutch prick, Dutch prik, Swedish prick "point, dot") of unknown etymology (see prick (v.)).

Figurative sense of "a goad" (to the affections, the conscience, etc.) was in Middle English. The meaning "pointed weapon, dagger" is attested from 1550s. From the Old English sense of "dot or small mark made in writing" came the Middle English use, in music, "mark indicating pitch" (compare counterpoint (n.2)); hence prick-song (mid-15c.) "music sung from written notes" instead of from memory or by ear.

It had many entwined extended senses in Middle English and early modern English, such as "a point marking a stage in progression," especially in the prick "the highest point, apex, acme;" and from the notion of "a point in time," especially "the moment of death" (prike of deth).

The use in kick against the pricks (Acts ix.5, first in the translation of 1382) probably is from sense of "a goad for oxen" (mid-14c.), which made it a plausible translation of Latin stimulus: advorsum stimulum calces was proverbial in Latin, and the English phrase also was used literally. The notion in the image is "to balk, be recalcitrant, resist superior force." The noun also was used in the 1384 Wycliffe Bible in 2 Corinthians xii.7, where the Latin is stimulis carnis meæ:

And lest the greetnesse of reuelaciouns enhaunce me in pride, the pricke of my fleisch, an aungel of Sathanas, is ʒouun to me, the which boffatith me.

Earliest recorded slang use for "penis" is 1590s (Shakespeare puns upon it). The verb prick was used in a figurative sense "have sexual intercourse with" (a woman) in Chaucer (late 14c.). My prick was used 16c.-17c. as a term of endearment by "immodest maids" for their boyfriends. As a term of abuse to a man, it is attested by 1929. Prick-teaser is attested from 1958.