detergent vs janitor

detergent

noun
  • Any non-soap cleaning agent, especially a synthetic surfactant. 

adj
  • Synonym of cleansing. 

janitor

noun
  • Someone who looks after the maintenance and cleaning of a public building. 

  • A caretaker or custodian; someone who maintains a school building specifically and may serve other administrative roles. 

  • A doorman. 

  • A moderator for a discussion forum. 

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