bedfellow vs companion

bedfellow

noun
  • An associate, often an otherwise improbable one. 

  • One with whom one shares a bed. 

companion

noun
  • A friend, acquaintance, or partner; someone with whom one spends time or accompanies 

  • A knot in whose neighborhood another, specified knot meets every meridian disk. 

  • An appended source of media or information, designed to be used in conjunction with and to enhance the main material. 

  • A celestial object that is associated with another. 

  • A knight of the lowest rank in certain orders. 

  • The covering of a hatchway on an upper deck which leads to the companionway; the stairs themselves. 

  • The framework on the quarterdeck of a sailing ship through which daylight entered the cabins below. 

  • A thing or phenomenon that is closely associated with another thing, phenomenon, or person. 

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