memorial (adj.)
late 14c., "memorable, excellent; remembered, committed to memory," from Old French memorial "mindful of, remembering," from Latin memorialis (adj.) "of or belonging to memory," from memoria "memory" (see memory).
memorial (n.)
late 14c., "fame, renown, reputation," also "commemorative gesture, monument, or rite;" in general, "something by which the memory of a person, thing, or event is preserved," from Old French memorial "record, report," and directly from Late Latin memoriale "a memorial," noun use of neuter of Latin memorialis (adj.) "of or belonging to memory," from memoria "memory" (see memory). Meaning "memorial act, commemoration" is from mid-15c.