Dictionary of Medieval Names
from European Sources

Monday m. Middle English Monday, Monenday, from Old English mōnandæġ 'day of the moon'.

This name is part of a pattern of names in English deriving from the names of days. Cf., e.g., Loveday, Pasca, Tiffany, etc.

England
Early Modern English
1544/5 Munday RegIng p. 2
Cite as: S.L. Uckelman. "Monday". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2019, no. 1. http://dmnes.org/2019/1/name/Monday.