Source : Webster's Revised Unabridged Dictionary (1913)

Coamings \Coam"ings\, n. pl. [Cf. {Comb} a crest.] (Naut.)
   Raised pieces of wood of iron around a hatchway, skylight, or
   other opening in the deck, to prevent water from running
   bellow; esp. the fore-and-aft pieces of a hatchway frame as
   distinguished from the transverse head ledges. [Written also
   {combings}.]