1Roman Catholic Church
The commemoration of a deceased person by the celebration of a requiem mass, prayers, etc., on a day one month from the date of the death or funeral.
2dialect Used allusively or humorously as a synonym for "mind": an inclination, fancy, liking. Especially in "to have (also bear) a month's mind". "to be in a month's mind": to have a strong expectation (rare).
Late Middle English. From the genitive of month + mind. Compare post-classical Latin dies mensis, dies mensis obitus.