relationship vs tie-up

relationship

noun
  • The level or degree of affinity between keys, chords and tones. 

  • The links between the x-values and y-values of ordered pairs of numbers especially coordinates. 

  • Connection or association; the condition of being related. 

  • Kinship; being related by blood or marriage. 

  • A romantic or sexual involvement. 

  • A way in which two or more people behave and are involved with each other 

tie-up

noun
  • A temporary interruption or cessation of a normal activity 

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