Region of calms, light variable winds, and thunderstorms, girdling the oceans near the equator and varying in position and extent according to the season.
The Doldrums, also called the "equatorial calms", is a nautical term for the equatorial trough, with special reference to the light and variable nature of the winds. [1]
dol·drums (d l dr mz, dôl-, d l-) pl.n. (used with a sing. or pl. verb) 1. a. A period of stagnation or slump. b. A period of depression or unhappy listlessness.