lookout vs onlook

lookout

noun
  • A subject for observation; a prospect or view. 

  • A session of watching for an approaching enemy, police, etc. 

  • A person on watch for approaching enemy, police, danger, etc. 

  • A vantage point with a view of the surrounding area. 

  • A joist that extends in cantilever out from the exterior wall (or wall plate) of a building, supporting the roof sheathing and providing a nailing surface for the fascia boards. 

  • An observation window. 

  • One's perspective, outlook; hence, one's responsibility. (used with a possessive pronoun or a noun in a possessive form). 

onlook

noun
  • The act of looking on (something); observation. 

  • One's perspective or outlook. 

  • That which is looked at, regarded, or considered. 

verb
  • To look on or look at; watch; observe; view; regard. 

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