Proto-Indo-European root meaning "to cover, conceal, save."

It forms all or part of: Anselm; apocalypse; Brussels; caliology; Calypso; calyx; ceiling; cell; cellar; cellular; cellulite; cellulitis; cilia; clandestine; cojones; coleoptera; color; conceal; eucalyptus; hall; hell; helm (n.2) "a helmet;" helmet; hold (n.2) "space in a ship below the lower deck;" hole; hollow; holster; housing (n.2) "ornamental covering;" hull (n.1) "seed covering;" kil-; kleptomania; occult; rathskeller; supercilious; Valhalla; William.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit cala "hut, house, hall;" Greek kalia "hut, nest," kalyptein "to cover," koleon, koleos "sheath," kelyphos "shell, husk;" Latin cella "small room, store room, hut," celare "to hide, conceal," clam "secret," clepere "to steal, listen secretly to;" Old Irish cuile "cellar," celim "hide," Middle Irish cul "defense, shelter;" Gothic hulistr "covering," Old English heolstor "lurking-hole, cave, covering," Gothic huljan "to cover over," hulundi "hole," hilms "helmet," halja "hell," Old English hol "cave," holu "husk, pod;" Old Prussian au-klipts "hidden;" Old Church Slavonic poklopu "cover, wrapping."

sea nymph in the "Odyssey," literally "hidden, hider" (perhaps originally a death goddess) from Greek kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save," which also is the source of English Hell. The type of West Indian song is so called from 1934, but the origin of the name is obscure.

euphemistic alteration of hell, by 1865.

1930s, college slang, from hell + fanciful ending (see bodacious).

also hellbent, "recklessly determined," 1824, U.S., originally slang, from hell + bent (adj.).

also hell-cat, "volatile woman," c. 1600, from hell + cat (n.). OED suggests "possibly suggested by Hecat," a spelling of Hecate.

also hell-fire, "the fire of Hell, eternal torment," from Old English hellefyr, in which helle is the genitive case of hell. It translates Greek gehenna tou pyros, literally "hell of fire." Also used in Middle English for "erysipelas" (mid-15c.).

also Hell-gate, "the entrance to Hell," Old English hellegat; see hell + gate (n.).

also hellhole, late 14c., "the pit of Hell," from hell + hole (n.). Meaning "very unpleasant place" is from 1866.

also hellhound, "wicked person, agent of Hell" (c. 1400), from Old English hellehund "Cerberus;" see hell + hound (n.). Similar formation in Dutch helhond, German Höllenhund.