pulley mortise
/ˈpʊli ˌmɔːtɪs/Woodworking and Joinery
noun
A long mortise such as may be used to form a housing for a pulley in the side jamb of a sash window frame; (also) a long shallow horizontal mortise for installing ceiling joists from below.
Origin
Mid 18th century; earliest use found in Francis Price (bap. 1699, d. 1753), architectural surveyor and author. From pulley + mortise.