Source : Webster's Revised Unabridged Dictionary (1913)

Thowel \Thow"el\, Thowl \Thowl\, n. [See {Thole}.] (Naut.)
   (a) A thole pin.
   (b) A rowlock.

             I would sit impatiently thinking with what an
             unusual amount of noise the oars worked in the
             thowels.                             --Dickens.