Definition from Wiktionary, the free dictionary
doldrums (plural only)
- 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
- 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