WordNet sense 1 (someone who bets):

bettor, punter, wagerer

WordNet sense 2 (surpass in excellence):

break

WordNet sense 3 (from a position of superiority or authority):

best

WordNet sense 4 (become or made better in quality):

improved

WordNet sense 5 (to make better):

ameliorate, amend, improve, meliorate

WordNet sense 6 (worthy of being recommended or suggested; prudent or wise):

advisable