Con-vĕn’tion-al, a.

a. [Lat. conventionalis, It. convenzionale, Sp. convencional, Fr. conventionnel.]

1. Formed by agreement or compact; stipulated. Conventional services reserved by tenures on grants, made out of the crown or knights’ service. Hale.
2. Growing out of, or depending on, custom or tacit agreement; sanctioned by usage. “Conventional decorum.” Whewell. “The conventional language appropriated to monarchs.” Motley.