toss up vs toss-up

toss up

verb
  • To produce, generate. 

  • To casually mention as an idea. 

  • To vomit. 

  • To beat up, thrash. 

  • To make a decision based on chance, for example by flipping a coin or rolling a dice. 

  • To cook something quickly. 

  • To throw something upwards. 

toss-up

noun
  • A decision in which neither choice is clearly favorable or unfavorable, or for which the outcome does not matter. 

  • Either of two outcomes that are equally likely. 

  • The toss of a coin used to decide some issue. 

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