pan head1
noun
A head of a rivet, bolt, screw, etc., shaped like an inverted flat-bottomed pan; frequently attributive.
Origin
Mid 19th century; earliest use found in Edward James Reed (1830–1906), naval architect.
pan head2
noun
A mechanism at the top of a tripod or other mount that allows the camera to move in both horizontal and vertical planes; a pan-and-tilt head.
Origin
1940s; earliest use found in American Speech.