COUNTERSINK v. 2 definitions
To chamfer or form a depression around the top of (a hole in wood, metal, etc.) for the reception of the head of a screw or bolt below the surface, either wholly or in part; as, to countersink a hole for a screw.
COURTESY n.
An act of civility, respect, or reverence, made by women, consisting of a slight depression or dropping of the body, with bending of the kness. [Written also curtsy.] The lady drops a courtesy in token of obedience, and the ceremony proceeds as usual. Golgsmith.