expander

To increase the size, volume, quantity, or scope of; enlarge: expanded her store by adding a second room. See Synonyms at increase.

To express at length or in detail; enlarge on: expanded his remarks afterward.

To open (something) up or out; spread out: The bird expanded its wings and flew off.

Mathematics To write (a quantity) as a sum of terms in an extended form.

To become greater in size, volume, quantity, or scope: Air expands when heated. This critic's influence is expanding.

To speak or write at length or in detail: expand on a favorite topic.

To open up or out; unfold: The chair expands to form a day bed.

To feel expansive.