Opposite of "expanded"?

Solution 1:

Contract

The wood contracted.

See the second definition.

v.intr. 1. To enter into or make an agreement: contract for garbage collection. 2. To become reduced in size by or as if by being drawn together: The pupils of the patient's eyes contracted.

=== edit Added antonyms and usage ===

For other opposites, try http://www.synonym.com/antonyms/expanded/.

Antonym of contract (Sense 9) =>abridge, foreshorten, abbreviate, shorten, cut, contract, reduce"

Here, I'm using expanded and its antonym as a transitive verb.

He expanded/abridged his novel.

She expanded/foreshortened her perspective.

He expanded/abbreviated his speech.

She expanded/shortened her trip.

They expanded/cut her research budget.

Here, I'm using expanded and its antonym as an intransitive verb

The bridge expanded/contracted as the temperature changed.

His waistline expanded/reduced with exercise.

Solution 2:

In computer applications design, we usually use components that have an accordion behavior. In that sense, we call the opposite of expand as collapse.

You can see an example of that behavior here.