- an archaic word for week
WordReference Random House Unabridged Dictionary of American English © 2026
sen•night
(sen′īt, -it),USA pronunciation n. [Archaic.]
- a week.
- Middle English sevenyht, seoveniht(e), sennyght, etc., Old English seofon nihta. See seven, night bef. 1000
Collins Concise English Dictionary © HarperCollins Publishers::
sennight, se'nnight /ˈsɛnaɪt/ n