- A trough or sluice having cleats, grooves, or steps across
the bottom for holding quicksilver and catching particles of gold when
auriferous earth is washed; also, one of the cleats, grooves, or steps
in such a trough. Also called ripple.
Meaning of 'riffle' (Princeton's WordNet)
1 . riffle
[ v]
Meaning (1): - look through a book or other written material