oarlock

A device, usually a U-shaped or circular metal hoop on a swivel in the gunwale, used to hold an oar in place and as a fulcrum in rowing.

A rowlock.

The notch, fork, or other device on the gunwale of a boat, in which the oar rests, and that holds the oar in place and acts as a fulcrum for rowing. Certain oarlocks are designed for use with oars having attached swivels, which insert into the oarlock and provide a firm pivot. Same as rowlock{1}.

A device attached to the gunwale of a rowboat to hold the oars in place while rowing.

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