from The American Heritage® Dictionary of the English Language, 4th Edition
- n.pl. Either of two belts of latitudes located over the oceans at about 30° to 35° north and south, having high barometric pressure, calms, and light, changeable winds.
from the GNU version of the Collaborative International Dictionary of English
- n. a space in the North Atlantic famous for calms and baffling winds, being between the westerly winds of higher latitudes and the trade winds.
from The Century Dictionary and Cyclopedia
- Nautical, a part of the North Atlantic ocean between the region of westerly winds of higher latitudes and the region of the trade-winds of the tropics, notorious for tedious calms.
Possibly from Spanish golfo de las yeguas, mares' sea.(American Heritage® Dictionary of the English Language, Fourth Edition)