Of or pertaining to. Adjectival suffix appended to various words, often nouns, to produce an adjective form. Often added to words of Latin origin, but used with other words also. · (no longer productive) Ending of some substantives borrowed or inherited from Latin and French.
From legend + -ary; from Medieval Latin legendārius. Earlier it was a noun meaning "a collection of legends" (1510s) (Medieval Latin legendārium, Old French legendier), from Latin legenda. In English, both the noun and the adjective first appeared in the 16th century.