What are doldrums why are they called so?

The doldrums is an area of the ocean. It is near the equator. The main thing is the wind is very calm. Sometimes there is no wind for a long time. This is because it is where trade winds from the north and south come together. The air gets warm and it goes up. It does not blow sideways to push a boat.

This was a big problem for old sailing ships. They got stuck for days or even weeks. With no wind, they could not go anywhere. The sailors felt very sad, bored, and stuck. In English, this feeling is called ‘being in the doldrums’. So, they called this calm part of the ocean 'the doldrums' because of how it made them feel.