1Happening at or near the time of an equinox.
- ‘They are also equinoctial tides, occurring just after the autumn equinox on September 23, which would normally bring the highest tides of the year.’
- ‘Two large stones also stand almost due east and west to mark the local equinoctial positions of the sun.’
- ‘You know, it's s good thing you're coming at the beginning of the month - that way you won't feel the force of the equinoctial storms’
- ‘That's the simple explanation anyway - you can check the exact equinoctial dates and times here, if you're so inclined.’
- ‘But Numa may also have had an equinoctial birthday.’
- ‘Outside, the equinoctial storms of mid-September are raging.’
- ‘The nights start drawing in quite quickly, and by late September the first of the equinoctial gales will have appeared with the weather in the hills of Scotland turning decidedly chilly at times.’
- 1.1Relating to equal day and night.
- ‘One of the effects of equinoctial periods is their temporary disruptive effect on communications satellites.’
- ‘The sundial above, dated 1509, shows equinoctial hours with a gnomon parallel to the earth's axis.’
- 1.2At or near the equator.
- ‘The Orinoco, the Eio Magdalena, and the Congo or Zaire, are the only great rivers of the equinoctial region of the globe.’
- ‘Lindley has made us acquainted with a species of Salix belonging to Senegal, and therefore to the equinoctial region of Africa.’
- another term for celestial equator
- ‘A star on the north side of the equinoctial is in northern declination, and one on the southern side is in southern declination.’
- ‘The declination of a heavenly body is its angular distance from the equinoctial or celestial equator.’
Late Middle English (in the sense relating to equal periods of day and night): via Old French from Latin aequinoctialis, from aequinoctium (see equinox).