Gill
Middle English: from Old Norse.
wiktionary
From Middle English gile(“gill”) (early 14th century), of Scandinavian origin, akin to Swedish gäl, Danish gælle, Norwegian gjelle, and further to Old Norse gjǫlnar(“lips”), which also may have had the meaning of "gills" (based on Old Danish fiskegæln(“gills”)). The Old Norse word has been suggested as deriving from Proto-Germanic *gelunaz(“jaw”), which would make it root-cognate to Ancient Greek χελυνη(khelunē, “lip, jaw”), χεῖλος(kheîlos, “lip”).
From Middle English gille, from Old French gille(“a wine measure”), from Medieval Latin gillo(“earthenware jar”), possibly from Gaulish gallā(“vessel”).
From Middle English gille, from Old Norse gil
Etymology uncertain.
(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)
Clipping of gillian, from the female name Gillian.
etymonline
gill (n.1)
"organ of breathing in fishes," early 14c., of unknown origin, perhaps related to Scandinavian words, such as Old Norse gjölnar which perhaps means "gills," and Old Danish -gæln (in fiske-gæln "fish gill"); said to be ultimately from a PIE *ghel-una- "jaw" (cognate: Greek kheilos "lip"). Related: Gills.
gill (n.2)
liquid measure (in modern use commonly a quarter of a pint), late 13c., from Old French gille, a wine measure, and from Medieval Latin gillo "earthenware jar," words of uncertain origin, perhaps related to the source of gallon.
Gill
fem. proper name, shortened form of Gillian. Also see Jill. Gill-flirt "giddy young woman" is from 1630s.
