boost vs expansion

boost

noun
  • A positive intake manifold pressure in cars with turbochargers or superchargers. 

  • A coordinate transformation that changes velocity. 

  • A push from behind, as to one who is endeavoring to climb. 

  • Something that helps, or adds power or effectiveness; assistance. 

verb
  • To lift or push from behind (one who is endeavoring to climb); to push up. 

  • To steal. 

  • To give a booster shot to. 

  • To help or encourage (something) to increase or improve; to assist in overcoming obstacles. 

  • To amplify; to signal boost. 

  • To jump-start a vehicle by using cables to connect the battery in a running vehicle to the battery in a vehicle that won't start. 

expansion

noun
  • The operation of steam in a cylinder after its communication with the boiler has been cut off, by which it continues to exert pressure upon the moving piston. 

  • A new addition. 

  • A product to be used with a previous product. 

  • That which is expanded; expanse; extended surface. 

  • The replacement of a short name (e.g., acronym, initialism, alphanumeric symbol, abbreviation) with the longer name that is synonymous with it, as when spelling out acronyms to ensure clarity for a general audience. 

  • The string of text thus substituted. 

  • An act, process, or instance of expanding. 

  • The fractional change in unit length per unit length per unit temperature change. 

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