CASTLE-GUARD

Cas″tle–guard′ (?), n. 1. 1. The guard or defense of a castle.
2. 2. (O. Eng. Law) A tax or imposition an a dwelling within a certain distance of a castle, for the purpose of maintaining watch and ward in it; castle-ward.
3. 3. A feudal tenure, obliging the tenant to perform service within the realm, without limitation of time.