definition of
expansion

[1] #1 expansion n. [enlargement] the act of increasing (something) in size or volume or quantity or scope. wn

[2] #2 expansion n. a function expressed as a sum or product of terms; "the expansion of (a+b)^2 is a^2 + 2ab + b^2". wn

[3] #3 expansion n. [enlargement, elaboration] a discussion that provides additional information. wn

[4] #4 expansion n. [expanding upon] adding information or detail. wn