seawater vs watered-down

seawater

adj
  • Consisting of seawater. 

  • Associated in some way with seawater, or intended for dealing with seawater. 

noun
  • The saltwater of a sea or ocean. 

watered-down

adj
  • Diluted; containing extra water. 

  • Weakened or simplified 

How often have the words seawater and watered-down occurred in a corpus of books? (source: Google Ngram Viewer )