What does expand mean?

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From our dictionary:

ex•pand

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.