(computing) A module that adds new content to an existing piece of software. / (video games, by extension) An add-on for a video game that includes additional content and is typically sold separately.

(physics) The cooling of a gas as it undergoes adiabatic expansion

(computing) The source code (assembler or other language) created by interpretation of a macro

plural of expansion adapter

plural of expansion joint

plural of expansion cleat

(physics) A logarithmic approximation used to calculate the momentum of a subatomic particle.

turboexpander

plural of expansion turbine

(mathematics) An expression for the determinant |B| of an n × n matrix B that is a weighted sum of the determinants of n submatrices (or minors) of B, each of size (n − 1) × (n − 1).