convection vs stir

convection

noun
  • The transmission of heat in a fluid by the circulation of currents. 

  • The vertical movement of heat and moisture, especially by updrafts and downdrafts in an unstable air mass. The terms convection and thunderstorm are often used interchangeably, although thunderstorms are only one form of convection. Towering cumulus clouds are visible forms of convection. 

stir

noun
  • The act or result of stirring (moving around the particles of a liquid etc.) 

  • agitation; tumult; bustle; noise or various movements. 

  • Public disturbance or commotion; tumultuous disorder; seditious uproar. 

  • Jail; prison. 

  • Agitation of thoughts; conflicting passions. 

verb
  • To incite to action. 

  • Of a feeling or emotion: to rise, begin to be felt. 

  • To disturb the relative position of the particles of (a liquid or similar) by passing an object through it. 

  • To begin to move, especially gently, from a still or unmoving position. 

  • To be in motion; to be active or bustling; to exert or busy oneself. 

  • To bring into debate; to agitate. 

  • To rise from sleep or unconsciousness. 

  • To disturb the content of (a container) by passing an object through it. 

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