topgallant mast

a mast fixed to the head of a topmast on a square-rigged vessel.

Origin of topgallant mast

First recorded in 1505–15

The mast-rope employed to sway up a top-mast or topgallant-mast, in order to fix it in its place, or lower it.

The Sailor's Word-Book |William Henry Smyth
Masts: The masts of a full-rigged three-masted ship are the following: Fore-mast, topmast, topgallant-mast, royal mast.

Anson's Voyage Round the World |Richard Walter
So we climbed up to the cap of the topgallant-mast in company; but, as far apart as the poles, though so close together.

Young Tom Bowling |J.C. Hutcheson
A yet smaller mast, elevated through irons at the head of the topgallant-mast; but more generally the two are formed of one spar.

The Sailor's Word-Book |William Henry Smyth

I knows her by the way her fore-topmast and topgallant-mast is looking over her bows.

Under the Meteor Flag |Harry Collingwood