Pronunciation: (ik-spand'),[key] —v.t. 1. to increase in extent, size, volume, scope, etc.: Heat expands most metals. He hopes to expand his company. 2. to spread or stretch out; unfold: A bird expands its wings. 3. to express in fuller form or greater detail; develop: to expand a short story into a novel. 4. Math. a. to write (a mathematical expression) so as to show the products of its factors. Cf. factor (def. 10).
b. to rewrite (a mathematical expression) as a sum, product, etc., of terms of a particular kind: to expand a function in a power series.
—v.i. 1. to increase or grow in extent, bulk, scope, etc.: Most metals expand with heat. The mind expands with experience. 2. to spread out; unfold; develop: The buds had not yet expanded. 3. to express something more fully or in greater detail (usually fol. by on or upon): to expand on a statement.