ETYMOLOGY
? possibly connected with gig (an eccentric person)
EXAMPLE
“…Hereupon it fell out, after the expiring of a scantling of Weeks, that Master Carvel became as jealous as a Tygar, and entred into a very profound suspition, that his new-married Gixy did keep a Buttock-stirring with others: to prevent which inconveniency, he did tell her many tragical Stories of the total Ruine of several Kingdoms by Adultery…”
From: The Third Book of the Heroick Deeds and Sayings of the good Pantagruel.
By Francois Rabelais
Translated by Thomas Urquhart, 1693
Lexicophilia 