double date vs entanglement

double date

noun
  • A (romantic) date that two couples go on together. 

verb
  • To go on a double date. 

entanglement

noun
  • The condition, or an instance, of being romantically or sexually involved with another person; an affair. 

  • An obstruction of cables and spars across a river or harbour entrance. 

  • The condition of being deeply involved and intricated (with politics, a group, another person, etc.) 

  • The act of entangling. 

  • An obstruction placed in front or on the flank of a fortification, to impede an enemy's approach. 

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