1. To open; to spread; as, a flower expands its leaves.
2. To spread; to enlarge a surface; to diffuse; as, a stream expands its waters over a plain.
3. To dilate; to enlarge in bulk; to distend; as, to expand the chest by inspiration; heat expands all bodies; air is expanded by rarefaction.
4. To enlarge; to extend; as, to expand the sphere of benevolence; to expand the heart or affections.