Learn how to say Equinoctial correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word equinoctial:
happening at or near the time of an equinox:
having a day and night of equal length.
at or near the equator:
the equinoctial region of the ocean
(also equinoctial line)another term for 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)