Source : Webster's Revised Unabridged Dictionary (1913)

Fore-topmast \Fore`-top"mast\, n. (Naut.)
   The mast erected at the head of the foremast, and at the head
   of which stands the fore-topgallant mast. See {Ship}.

Source : WordNet®

fore-topmast
     n : the topmast next above the foremast