Old English carian, cearian "be anxious or solicitous; grieve; feel concern or interest," from Proto-Germanic *karo- "lament," hence "grief, care" (source also of Old Saxon karon "to lament, to care, to sorrow, complain," Old High German charon "complain, lament," Gothic karon "be anxious"), said to be from PIE root *gar- "cry out, call, scream" (source also of Irish gairm "shout, cry, call;" see garrulous).
If so, the prehistoric sense development is from "cry" to "lamentation" to "grief." A different sense evolution is represented in related Dutch karig "scanty, frugal," German karg "stingy, scanty." It is not considered to be related to Latin cura. Positive senses, such as "have an inclination" (1550s); "have fondness for" (1520s) seem to have developed later as mirrors to the earlier negative ones.
To not care as a negative dismissal is attested from mid-13c. Phrase couldn't care less is from 1946; could care less in the same sense (with an understood negative) is from 1955. Care also has figured since 1580s in many "similies of indifference" in the form don't care a _____, with the blank filled by fig, pin, button, cent, straw, rush, point, farthing, snap, etc., etc. Related: Cared; caring.
1838, American English, apparently originally the name of some kind of alcoholic drink, of unknown origin. It has joined that class of words (such as dingus, doohickey, gadget, gizmo, thingumabob) which are conjured up to supply names for items whose proper names are unknown or not recollected. Used at various periods for "money," "a professional tramp," "a muffin," "male genitalia," "a Chinese," "an Italian," "a woman who is neither your sister nor your mother," and "a foolish person in authority." Popularized in sense of "foolish person" by U.S. TV show "All in the Family" (1971-79), though this usage dates from 1905. In typography, by 1912 as a printer's term for ornament used in headline or with illustrations.
About 10:30 o'clock there was a snap of breaking metal, and the machine was stopped. It was discovered that the gilderfluke had come into contact with the dudad which operates the dingus on the diaphason, thereby letting the Johnson bar oscillate as it were between Alpha and Omega, thus preventing the dingbat from percolating the perihelion of the gazabo, and causing the dofunny on the parallelogram to drop into oblivion. [from an Illinois newspaper's account of a production delay caused by a Linotype machine breakdown, reprinted in Inland Printer, Chicago, February 1903]
late Old English pinn "peg or bolt of wood or metal used to hold things in place or fasten them together," from Proto-Germanic *penn- "jutting point or peak" (source also of Old Saxon pin "peg," Old Norse pinni "peg, tack," Middle Dutch pin "pin, peg," Old High German pfinn, German Pinne "pin, tack") from Latin pinna "a feather, plume;" in plural "a wing;" also "fin, scoop of a water wheel;" also "a pinnacle; a promontory, cape; battlement" (as in Luke iv.9 in Vulgate) and so applied to "points" of various sorts, from PIE root *pet- "to rush, to fly."
De Vaan and Watkins say Latin pinna is a derivative of penna, literally "feather" (see pen (n.1)); older theories regarded pinna as a separate word from a root meaning "sharp point." The Latin word also was borrowed in Celtic: Irish pinne "a pin, peg, spigot;" Welsh pin "a pin, pen."
The transition from 'feather' to 'pin' (a slender or pointed instrument) appears to have been through 'pen,' a quill, to ' pen,' a style or stylus, hence any slender or pointed instrument [Century Dictionary]
As a part of a lock or latch, c. 1200; as a control for a mechanical device, late 14c. The modern slender wire pin, used as a fastener for clothing or in sewing, is attested by this name by late 14c., perhaps late 13c. Transferred sense of "leg" is recorded from 1520s and holds the older sense. The meaning "wooden stick or club set up to be knocked down in a game" (skittles, bowling, etc.) is by 1570s.
Pin-money "annual sum allotted to a woman for personal expenses on dress, etc." is attested from 1620s. Pins and needles "tingling sensation" is from 1810. The sound of a pin dropping as a type of something all but silent is from 1775.
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.