The Collaborative International Dictionary of English v.0.48:

broad-headed \broad-headed\ adj.
   having a broad head. [Narrower terms: brachycephalic (vs.
   dolichocephalic), brachycranal, brachycranic]

   Syn: roundheaded, short-headed.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

broad-headed
    adj 1: having a brachycephalic head [syn: broad-headed,
           roundheaded, short-headed]