a mild state of mania, especially as a phase of a manic-depressive cycle
This word appears in the New York Times Magazine: “This year, two professors of psychiatry … argue that the United States is full of energetic risk-takers because it’s full of immigrants, who as a grop my carry a genetic marker that expresses itself as restless curiosity, exuberance and competitive self-promotion — a combination known as hypomania.”