fastern's e'en
noun
fast·ern's e'en
ˌfasərnˈzēn
variants or fastern's
ˈfasərnz
chiefly Scottish
: shrove tuesday
Word History
Etymology
Middle English (Scots) fasternis evin, from fasternis (genitive of fastern fast, from Old English—Northumbrian dialect—fæstern, from Old English fæstan to fast) + evin