a reddish mark left on the skin by a passionate kiss.
2.
any device or gadget whose name is not known or is momentarily forgotten.
3.
Electricity. a fitting used to mount a lighting fixture in an outlet box or on a pipe or stud.
4.
a tool used to bend tubes and pipes.
Also, hickie.
Origin
1905-10; Americanism; of obscure origin; senses under def. 1 perhaps a separate word, though the development “device > defective device > defect, blemish, mark” is also possible; cf. doohickey
British Dictionary definitions for hickey
hickey
/ˈhɪkɪ/
noun
1.
(US & Canadian, informal) an object or gadget: used as a name when the correct name is forgotten, etc; doodah
2.
(US & Canadian, informal) a mark on the skin, esp a lovebite
3.
(printing) a spot on a printed sheet caused by an imperfection or a speck on the printing plate
Any unspecified or unspecifiable object; something one does not know the name of or does not wish to name; doodad, doohickey, gadget: We have little hickeys beside our seats(1909+)
A blackhead, pimple, or other minor skin lesion; zit(1915+)
A mark on the skin made by biting or sucking during a sex act: line of hickeys, or love bites/ Violet came home from the mall with a leather bustier and a hickey(1956+)