high tide vs rag week

high tide

noun
  • Synonym of menstruation 

  • The natural tide at its highest level for a particular tidal cycle at a certain place. 

  • climax, culminating point or phase 

  • The time of day when the sea has risen to its highest level. 

rag week

noun
  • The days of the month when a woman has her period. 

  • An annual event in many universities where students engage in unusual activities to raise money for charity. 

How often have the words high tide and rag week occurred in a corpus of books? (source: Google Ngram Viewer )