of the equinox, usually referring to either the equator or a change of seasons during the equinox
► uses
Uses:
It was in the latter days of September, and the equinoctial gales had set in with exceptional violence.
Arthur Conan Doyle. Sherlock Holmes: The Five Orange Pips
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if I had here an astrolabe to take the altitude of the pole, I could tell thee how many we have travelled, though either I know little, or we have already crossed or shall shortly cross the equinoctial line which parts the two opposite poles midway."