Source : Webster's Revised Unabridged Dictionary (1913)

Strapper \Strap"per\, n.
   1. One who uses strap.

   2. A person or thing of uncommon size. [Colloq.]

Source : WordNet®

strapper
     n : a large and strong and heavyset man; "he was a bull of a
         man"; "a thick-skinned bruiser ready to give as good as
         he got" [syn: {bull}, {bruiser}, {Samson}]