Webster's Revised Unabridged Dictionary · 1913

Conventional

Conventional , adjective

[Latin conventionalis: compare French conventionnel.]

1.
Formed by agreement or compact; stipulated.
Conventional services reserved by tenures upon grants, made out of the crown or knights' service. — Sir M. Hale
2.
Growing out of, or depending on, custom or tacit agreement; sanctioned by general concurrence or usage; formal.
Conventional decorum. — Whewell
The conventional language appropriated to monarchs. — Motley
The ordinary salutations, and other points of social behavior, are conventional. — Latham
3.
(a) (Fine Arts) Based upon tradition, whether religious and historical or of artistic rules.
(b)
(Fine Arts) Abstracted; removed from close representation of nature by the deliberate selection of what is to be represented and what is to be rejected; as, a conventional flower; a conventional shell. Compare Conventionalize, transitive verb