'Beau' definitions:

Definition of 'beau'

From: WordNet
noun
A man who is the lover of a girl or young woman; "if I'd known he was her boyfriend I wouldn't have asked" [syn: boyfriend, fellow, beau, swain, young man]
noun
A man who is much concerned with his dress and appearance [syn: dandy, dude, fop, gallant, sheik, beau, swell, fashion plate, clotheshorse]

Definition of 'Beau'

From: GCIDE
  • Beau \Beau\ (b[=o]), n.; pl. F. Beaux (E. pron. b[=o]z), E. Beaus (b[=o]z). [F., a fop, fr. beau fine, beautiful, fr. L. bellus pretty, fine, for bonulus, dim. of bonus good. See Bounty, and cf. Belle, Beauty.]
  • 1. A man who takes great care to dress in the latest fashion; a dandy. [1913 Webster]
  • 2. A man who escorts, or pays attentions to, a lady; an escort; a suitor or lover. [1913 Webster]