riffle
UK[ˈrɪf(ə)l]US[ˈrɪf(ə)l]
v
To turn over papers, pages, or the leaves of a book quickly and casually.
v
To shuffle playing cards by lifting and releasing two halves of the deck so they intermingle.
n
A quick, casual, and often noisy flipping or shuffling of pages, papers, or cards.
n
A shallow, rocky, or fast-flowing part of a stream, often forming a small rapid.
Etymology
The verb 'riffle' first appeared in English in the late 18th century, likely as an alteration or frequentative form of the older verb 'ruffle', meaning to disturb the smoothness of something. The core sense of creating a rippling, fluttering, or shuffling motion is probably of onomatopoeic or expressive origin, imitating the sound of things being flipped or stirred quickly. This imitative root gave rise to both the action senses (shuffling cards, flipping pages) and the natural feature sense (a shallow, rippling part of a stream), which emerged in American English in the 19th century, describing water that is disturbed or broken over rocks. Thus, a single expressive root evolved to describe similar light, agitated motions in both manual and natural contexts.
Analysis
The word 'riffle' is a simplex word of uncertain origin, likely imitative or expressive in nature. It is not productively formed from distinct, separable morphemes in modern English.
Examples
She began to riffle through the stack of letters on her desk.
The dealer knows how to riffle the cards perfectly before a game of poker.
We pulled the canoe ashore just before reaching the rocky riffle.