"erectile organ of female mammals," 1610s, coined in Modern Latin from Late Greek kleitoris, a diminutive, but the exact sense intended by the coiners is uncertain. Perhaps from Greek kleiein "to sheathe," also "to shut," in reference to its being covered by the labia minora. The related Greek noun kleis has a secondary meaning "a key, a latch or hook (to close a door);" see close (v.), and compare slot (n.2).
Alternatively [Watkins], from Greek kleitys, a variant of klitys "side of a hill," from PIE *kleitor-, suffixed form of root *klei- "to lean," via with a sense of "little hill." Some ancient medical sources give a supposed Greek verb kleitoriazein "to touch or titillate lasciviously, to tickle" (compare German slang der Kitzler "clitoris," literally "the tickler"), but in this case the verb is likely from the anatomy.
As for the Greeks themselves, they seem to have called the thing nymphē, a figurative use, literally "bride, lovely young woman;" Beekes also has kystho-korone "clitoris," literally "crown of the vagina."
The anatomist Mateo Renaldo Colombo (1516-1559), professor at Padua, claimed to have discovered it ("De re anatomica," 1559, p. 243). He called it amor Veneris, vel dulcedo "the love or sweetness of Venus." It had been known earlier to women.
Proto-Indo-European root meaning "to lean."
It forms all or part of: acclivity; anticline; clemency; client; climate; climax; cline; clinic; clinical; clino-; clitellum; clitoris; decline; declivity; enclitic; heteroclite; incline; ladder; lean (v.); lid; low (n.2) "small hill, eminence;" matroclinous; patroclinous; polyclinic; proclitic; proclivity; recline; synclinal; thermocline.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit srayati "leans," sritah "leaning;" Old Persian cay "to lean;" Lithuanian šlyti "to slope," šlieti "to lean;" Latin clinare "to lean, bend," clivus "declivity," inclinare "cause to bend," declinare "bend down, turn aside;" Greek klinein "to cause to slope, slant, incline;" Old Irish cloin "crooked, wrong;" Middle Irish cle, Welsh cledd "left," literally "slanting").
head of the penis or clitoris, 1640s, from Latin glans "acorn," also used of acorn-shaped things (see gland).
mid-15c., "establishment; advancement," from Late Latin erectionem (nominative erectio), noun of action from past participle stem of erigere "to set up, erect" (see erect (adj.)). Meanings "the putting up" (of a building, etc.), "stiffening of the penis" (also sometimes of the turgidity and rigidity of the clitoris) are both from 1590s.
