let up vs stopper

let up

verb
  • To cease or stop. 

  • To cease or stop (doing something intense). 

stopper

verb
  • To close a container by using a stopper. 

noun
  • Any of several trees of the genus Eugenia, found in Florida and the West Indies. 

  • A bung or cork. 

  • In the commodity futures market, someone who is long (owns) a futures contract and is demanding delivery because they want to take possession of the deliverable commodity. 

  • A type of knot at the end of a rope, to prevent it from unravelling. 

  • A short rope for making something fast. 

  • Goalkeeper. 

  • A train that calls at all or almost all stations between its origin and destination, including very small ones. 

  • A playspot where water flows back on itself, creating a retentive feature. 

How often have the words let up and stopper occurred in a corpus of books? (source: Google Ngram Viewer )