Pronunciation: (ik-span'siv),[key] —adj. 1. having a wide range or extent; comprehensive; extensive: expansive mountain scenery. 2. (of a person's character or speech) effusive, unrestrained, free, or open: Our expansive host welcomed us warmly. 3. tending to expand or capable of expanding.
4. causing expansion: the expansive force of heat. 5. working by expansion, as an engine.
6. Psychiatry.marked by an abnormal euphoric state and by delusions of grandeur.