rowlock

An oarlock.

In architecture, characterized by having its voussoirs in concentric rings, one closely adjusted to another. The rowlock arch of brick is one in which each ring of brick voussoirs is only the width of the brick, or about four inches, in depth.

A contrivance on a boat’s gunwale in or on which the oar rests and swings freely in rowing.

A contrivance or arrangement serving as a fulcrum for an oar in rowing. It consists sometimes of a notch in the gunwale of a boat, sometimes of a pair of pins between which the oar rests on the edge of the gunwale, sometimes of a single pin passing through the oar, or of a metal fork or stirrup pivoted in the gunwale and suporting the oar; same as oarlock.

One of the rings of masonry included in an arch having more than one ring.

a pivot attached to the gunwale (outrigger in a sport boat) of a boat that supports and guides an oar, and provides a fulcrum for rowing; an oarlock (mostly US).

a holder attached to the gunwale of a boat that holds the oar in place and acts as a fulcrum for rowing