Definition from Wiktionary, the free dictionary
doldrums pl (plural only)
- (nautical) A part of the ocean near the equator, abounding in calms, squalls, and light, baffling winds, which sometimes prevent all progress for weeks.
- The state of boredom, malaise, apathy or lack of interest; a state of listlessness; ennui, or tedium
- I was in the doldrums yesterday and just didn't feel inspired.
(region near the equator):
part of the ocean near the equator, abounding in calms which prevent sailing progress