expansion

noun

• the action of becoming larger or more extensive:the rapid expansion of suburban London [count noun]:a small expansion of industry
• the political strategy of extending a state’s territory by encroaching on that of other nations:German expansion in the 1930s
• [count noun] a thing formed by the enlargement or broadening of something:the book is an expansion of a lecture given last year
• the increase in the volume of fuel on combustion in the cylinder of an engine, or the piston stroke in which this occurs.