[from the Anglo-Saxon thol]. Certain pins in the gunwale of a boat, instead of the rowlock-poppets, and serving to retain the oars in position when pulling; generally there is only one pin to each oar, which is retained upon the pin by a grommet, or a cleat with a hole through it, nailed on the side of the oar. The principal use is to allow the oar, in case of action, suddenly to lie fore-and-aft over the side, and take care of itself. This was superseded by the swinging thowel, or metal crutch, in 1819, and by admiralty order at Portsmouth Yard in 1830.