The story
- Proto-West Germanic · inherited from*murgiþu“briefness, brevity”
- Old English · inherited frommyrgþ“mirth, joy”
- Middle English · inherited frommerth
- English todaymirth
From Middle English merth, myrthe, murhthe, from Old English myrgþ (“mirth, joy”), from Proto-West Germanic *murgiþu (“briefness, brevity”); equivalent to merry + -th (abstract nominal suffix). Cognate with Middle Dutch merchte (“pleasure, joy, delight”).
Etymology from Wiktionary, CC BY-SA 4.0.