Definition of "Riffle" :

noun: shuffling by splitting the pack and interweaving the two halves at their corners

noun: a small wave on the surface of a liquid

verb: shuffle (playing cards) by separating the deck into two parts and riffling with the thumbs so the cards intermix

verb: twitch or flutter

verb: stir up (water) so as to form ripples

verb: look through a book or other written material