"of or pertaining to a manor or manors," 1775, from manor + -al (1).
Entries linking to manorial
manor n.
c. 1300, maner, "mansion, habitation, country residence, principal house of an estate," also "a manorial estate," from Anglo-French maner, Old French manoir "abode, home, dwelling place; manor" (12c.), noun use of maneir "to dwell," from Latin manere "to stay, abide," from PIE root *men- (3) "to remain." As a unit of territorial division in Britain and some American colonies (usually "land held in demesne by a lord, with tenants") it is attested from 1530s.
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).