riffle

noun

1. A swift, shallow part of a stream causing broken water.

   “They then proceeded below the milldam, where there was a strong riffle, with likely looking pools and eddies”

   “The big trout feed aggressively and tend to lose their caution in the rifles.”

   “[...] Brook Drain has now been diverted into a newly dug replacement river section [...]. It has been designed in conjunction with the Environment Agency to hold a much larger volume of water, in order to help with local flooding issues. It also features riffles (shallow sections of water) and side pools where aquatic wildlife can take shelter during storms.”

2. A succession of small waves.
3. 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 trough.
4. A quick skim through the pages of a book.
5. Synonym of riffle shuffle
6. The sound made while shuffling cards.
7. In seal engraving, a small metal disc at the end of a tool.

verb

1. (intransitive)To flow over a swift, shallow part of a stream.
2. (transitive)To ruffle with a rippling action.
3. (intransitive)To skim or flick through the pages of a book.
4. (transitive)To leaf through rapidly.

   “Near-synonym: rifle”

5. (transitive)To shuffle playing cards by separating the deck in two and sliding the thumbs along the edges of the cards to mix the two parts.
6. (transitive)To idly manipulate objects with the fingers.
7. (transitive)To prepare samples of material using a riffler.

name

1. A surname.