Ex*pand" (?), v. t. [imp. & p. p. Expanded; p. pr. & vb. n. Expanding.] [L. expandere, expansum; ex out + pandere to spread out, to throw open; perh. akin to E. patent. Cf. Spawn.] 1. To lay open by extending; to open wide; to spread out; to diffuse; as, a flower expands its leaves.

Then with expanded wings he steers his flight.

2. To cause the particles or parts of to spread themselves or stand apart, thus increasing bulk without addition of substance; to make to occupy more space; to dilate; to distend; to extend every way; to enlarge; -- opposed to contract; as, to expand the chest; heat expands all bodies; to expand the sphere of benevolence.

3. (Math.) To state in enlarged form; to develop; as, to expand an equation. See Expansion, 5.

Ex*pand", v. i. To become widely opened, spread apart, dilated, distended, or enlarged; as, flowers expand in the spring; metals expand by heat; the heart expands with joy. Dryden.

• To change from a smaller form to a larger one.
        You can expand this compact umbrella to cover a large table.
  
• (algebra) To rewrite an expression as an equivalent sum of terms.
        Use the binomial theorem to expand {(x+1)}^4 to x^4 + 4x^3 + 6x^2 + 4x + 1
  
• To become expanded through some process.
        Many materials expand when heated.
        This compact umbrella expands to cover a large table.
        The expression {(x+1)}^4 expands to x^4 + 4x^3 + 6x^2 + 4x + 1.