Why is the ninth month called September?
"to deceive (especially after holding out hopes), cheat, trick," 1660s, from the same source as jilt (n.). Related: Jilted; jilting.
1670s, "loose, unchaste woman; harlot;" also "woman who gives hope then dashes it," perhaps ultimately 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).