Selene

c. 1400, "faint with heat," frequentative of swelten "be faint (especially with heat)," late 14c., from Old English sweltan "to die, perish," from Proto-Germanic *swiltan- (source also of Old Saxon sweltan "to die," Old Norse svelta "to put to death, starve," Gothic sviltan "to die"), perhaps originally "to burn slowly," hence "to be overcome with heat or fever," from PIE root *swel- (2) "to shine, beam" (see Selene). From the same ancient root comes Old English swelan "to burn." For specialization of words meaning "to die," compare starve. Related: Sweltered; sweltering.

1590s, "oppressively hot, close and moist" (of weather), ultimately from swelter + alteration of -y (2), either as a contraction of sweltry or from obsolete verb sulter "to swelter" (1580s), alteration of swelter. Figurative sense of "hot with lust" is attested from 1704; of women, "lascivious, sensual, arousing desire" it is recorded from 1940. Related: Sultriness.