act of getting bigger, like an economy during a boom.

Phase of the business cycle as it climbs from a trough toward a peak.

A period of positive growth in the economy, starting from the point of the business cycle after the economy regained its pre- recession peak.

A phase of the business cycle that extends from a trough to the next peak. See business cycle. (NBER)

The business cycle has its ups and downs. The good times are called an expansion.