A gate is an entrance in a fence or wall; it usually swings on hinges. The default heraldic gate is a “corral gate”, sometimes called a “field-gate” or “farm-gate”; this is sometimes explicitly blazoned. The gate is drawn as a barred wooden frame, not solid like a door. It’s found in the arms of von Haxthausen, 1605 [Siebmacher 186]. The gate’s “proper” coloration, as with all wooden charges, is brown.
The Shire of Caversgate bears: Sable, a gate within and conjoined to a stone archway within a laurel wreath Or.
Eric of Coppergate bears: Argent, a farm gate within an orle engrailed gules.