gill n.1

English measure of capacity (containing four quarts), usually for liquids, late 13c., from Old North French galon, corresponding to Old French jalon, name of a liquid measure roughly equivalent to a modern gallon," which is related to (perhaps augmentative of) jale "bowl," from Medieval Latin or Vulgar Latin diminutive form galleta "bucket, pail," also "a measure of wine," a word of unknown origin, perhaps from Gaulish galla "vessel."

fem. proper name, from French Juliane, from Late Latin Juliana (a saint's name), fem. of Iulianus, literally "of Julius," the Roman gens name (see Julius).

fem. proper name, Middle English Jille, Jylle, Gille, etc., familiar shortening of Jillian, Gillian, which represent the common Middle English pronunciation of Juliana (see Gillian). A very popular name for girls in medieval England, hence its use as a familiar, almost generic, name for a girl (early 15c.; paired with Jack since mid-15c.).