n. 1. The guard or defense of a castle. [ 1913 Webster ]

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. [ 1913 Webster ]

3. A feudal tenure, obliging the tenant to perform service within the realm, without limitation of time. [ 1913 Webster ]