background vs primary

background

noun
  • One's social heritage, or previous life; what one did in the past. 

  • Information relevant to the current situation about past events; history. 

  • The image or color over which a computer's desktop items are shown (e.g. icons or application windows). 

  • A part of the picture that depicts scenery to the rear or behind the main subject; context. 

  • A less important feature of scenery (as opposed to foreground). 

  • A type of activity on a computer that is not normally visible to the user. 

adj
  • Less important or less noticeable in a scene or system. 

verb
  • To put in a position that is not prominent. 

  • To gather and provide background information (on). 

primary

verb
  • To challenge (an incumbent sitting politician) for their political party's nomination to run for re-election, through running a challenger campaign in a primary election, especially one that is more ideologically extreme. 

  • To take part in a primary election. 

noun
  • A directly driven inductive coil, as in a transformer or induction motor that is magnetically coupled to a secondary 

  • A primary school. 

  • A primary election; a preliminary election to select a political candidate of a political party. 

  • A radar return from an aircraft (or other object) produced solely by the reflection of the radar beam from the aircraft's skin, without additional information from the aircraft's transponder. 

  • Any flight feather attached to the manus (hand) of a bird. 

  • A base or fundamental component; something that is irreducible. 

  • The most massive component of a gravitationally bound system, such as a planet in relation to its satellites. 

  • The first year of grade school. 

  • A primary colour. 

  • Primary site of disease; original location or source of the disease. 

  • The first stage of a thermonuclear weapon, which sets off a fission explosion to help trigger a fusion reaction in the weapon's secondary stage. 

adj
  • Earliest formed; fundamental. 

  • first or earliest in a group or series. 

  • main; principal; chief; placed ahead of others. 

  • Relating to day-to-day care provided by health professionals such as nurses, general practitioners, dentists etc. 

  • Relating to the place where a disorder or disease started to occur. 

  • Illustrating, possessing, or characterized by, some quality or property in the first degree; having undergone the first stage of substitution or replacement. 

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