sneeringly

from WordNet (r) 3.0 (2006)

sneeringly
    adv 1: with a sneer; in an uncomplimentary sneering manner; "`I
           don't believe in these customs,' he said sneeringly"
           [syn: {sneeringly}, {superciliously}, {snidely}]

from The Collaborative International Dictionary of English v.0.48

Sneeringly \Sneer"ing*ly\, adv.
   In a sneering manner.
   [1913 Webster]