jilt v.

"to deceive (especially after holding out hopes), discard after encouraging," 1670s; earlier "to cheat, trick" (1660s); of uncertain origin (see jilt (n.)). Related: Jilted; jilting.

1670s, "loose, unchaste woman; harlot;" also "woman who gives hope then dashes it;" probably a contraction of jillet, gillet, from Middle English gille "lass, wench," a familiar or contemptuous term for a woman or girl (mid-15c.), originally a shortened form of woman's name Gillian (see Jill).