Doldrums is a belt of calms, light breezes, or sudden squalls near the equator, mainly over the oceans. Meteorologists call it the intertropic convergence zone. The name doldrums means listlessness. Sailors were the first to use this name for the region near the equator because their sailing ships often were becalmed (unable to sail) there.
In the doldrums, the air moves upward, causing sudden thunderstorms and gusty winds. The region is one of the rainiest in the world.