certain vs rocky

certain

adj
  • Actually existing; sure to happen; inevitable. 

  • Unfailing; infallible. 

  • Known but not specifically named; indeterminate; indefinite; one or some; sometimes used independently as a noun, and meaning certain persons; see also "one". 

  • Fixed or stated; regular; determinate. 

  • Not to be doubted or denied; established as a fact. 

  • Sure, positive, not doubting. 

det
  • Having been determined but not specified. 

pron
  • Unnamed or undescribed members (of). 

rocky

adj
  • Easily rocked; unstable. 

  • In the style of rock music. 

  • Abounding in, or full of, rocks; consisting of rocks. 

  • Like a rock; rigid, solid. 

  • Having a habitat around or on rocks. 

  • Encountering many problems; difficult, troubled; also, in danger or distress. 

  • Of a person: ill, or unsteady (for example, as a result of a shock). 

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