low water vs riffle

low water

noun
  • The lowest stage of a river. 

  • The temporary situation of having little money. 

  • The location of low tide in a coastal area. 

riffle

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

  • A succession of small waves. 

  • A quick skim through the pages of a book. 

  • 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. 

  • In seal engraving, a small metal disc at the end of a tool. 

  • The act of shuffling cards; the sound made while shuffling cards. 

verb
  • To ruffle with a rippling action. 

  • To skim or flick through the pages of a book. 

  • To flow over a swift, shallow part of a stream. 

  • 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. 

  • To leaf through rapidly. 

  • To idly manipulate objects with the fingers. 

  • To prepare samples of material using a riffler. 

How often have the words low water and riffle occurred in a corpus of books? (source: Google Ngram Viewer )