Source : Webster's Revised Unabridged Dictionary (1913)

Handbreadth \Hand"breadth`\, n.
   A space equal to the breadth of the hand; a palm. --Ex.
   xxxvii. 12.

Source : WordNet®

handbreadth
     n : any unit of length based on the breadth of the human hand
         [syn: {handsbreadth}]