Halibut

Next Wednesday, February 22nd, marks the beginning of Lent, a time when many people eat fish rather than meat for religious reasons. This practice is at the origin of the word “halibut”. Various kinds of flatfish were called “butt” in the Middle Ages, possibly because their heads had a blunt shape like the butt end of something. At the time, the word “holy” was pronounced HALLY or HOLLY. A “hally butt” was, therefore, a flatfish eaten on holy days, a “holy flatfish”.
Holy flatfish, Batman!