What's the difference between i.e. and e.g.?
early 13c., "an accessory," from Old French ornement "ornament, decoration," and directly from Latin ornamentum "apparatus, equipment, trappings; embellishment, decoration, trinket," from ornare "equip, adorn" (see ornate). Meaning "decoration, embellishment" in English is attested from late 14c. (also a secondary sense in classical Latin). Figurative use from 1550s.
1720, from ornament (n.). Middle English used ournen (late 14c.) in this sense, from Old French orner, from Latin ornare. Related: Ornamented; ornamenting.
in architecture, any element added to an otherwise merely structural form, usually for purposes of decoration or embellishment. Three basic and fairly distinct categories of ornament in architecture may be recognized: mimetic, or imitative, ornament, the forms of which have certain definite meanings or symbolic significance; applied ornament, intended to add beauty to a structure but extrinsic to it; and organic ornament, inherent in the building's function or materials