doldrums

n. boredom, dismal mood, depression; area of calm winds around the equator; inactivity, stagnation, idleness

The Intertropical Convergence Zone (ITCZ), also known as the Intertropical Front, Monsoon trough, Doldrums or the Equatorial Convergence Zone, is a belt of low pressure girdling Earth at the equator. It is formed by the vertical ascent of warm, moist air from the latitudes above and below the equator.
See more at Wikipedia.org...

Noun
1. a state of inactivity (in business or art etc); "economic growth of less than 1% per year is considered to be economic stagnation"
(synonym) stagnation, stagnancy
(hypernym) inaction, inactivity, inactiveness
(classification) commercial enterprise, business enterprise, business
2. a belt of calms and light winds between the northern and southern trade winds of the Atlantic and Pacific
(synonym) the doldrums
(hypernym) wind, air current, current of air

(n. pl.)
A part of the ocean near the equator, abounding in calms, squalls, and light, baffling winds, which sometimes prevent all progress for weeks; -- so called by sailors.
  

doldrums