'Topmast' definitions:
Definition of 'topmast'
(from WordNet)
noun
The mast next above a lower mast and topmost in a fore-and- aft rig
Definition of 'Topmast'
From: GCIDE
- Topmast \Top"mast\, n. (Naut.) The second mast, or that which is next above the lower mast, and below the topgallant mast. [1913 Webster]