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1.
Pronounced like "gan-zee"

Literally, this is the Irish word for jumper (which is the UK/Irish term for a sweater).

Used as an insult to imply that somebody has the intelligence of the aforementioned garment i.e. none at all
Louise: "Let's go shopping!"
Steven: "It's midnight, you're drunk, and we're in the pub. The shops are closed! You big geansaí!"
by Dan Jacobs December 06, 2007

Words related to geansaí

ganzee gan-zee irish jumper sweater