The Collaborative International Dictionary of English v.0.48:
Broadax \Broad"ax`\, Broadaxe \Broad"axe`\, broad-axe \broad-axe\, broad-ax \broad-ax\, n. 1. An ancient military weapon; a battle-ax. [1913 Webster] 2. An ax with a broad edge, for hewing timber. [1913 Webster]WordNet (r) 3.0 (2006):
broadax n 1: a large ax with a broad cutting blade [syn: broadax, broadaxe]