Jill is a variant of the proper name Gill, itself a female form either of Julius (then also Gillian or Jillian) or of Aegidius.
- given name|female|from Latin|
- generic use for any female (as Sheila in Australian English), especially paired (since the 15th c., compare Ienken and Iulyan) with the male Jack; also in the compound jillstrap (also shortened as jill), the female counterpart of a jockstrap
- A young woman; a sweetheart; like the variant spelling Gill it was also associated with various assertive uses of the term flirt, as in flirtgigg (used by William Shakespeare for a 'woman of light or loose behavior').
- A term used to describe your right hand, usually hinting at masturbation.
Dr. Jan Van der Schaar, Woordenboek van voornamen (onomasticon in Dutch), Utrecht-Antwerpen, Het Spectrum (Aula series), 1963 (reprint 1979)