vernal equinox Syllabification: (ver·nal e·qui·nox)Definition of vernal equinox noun the equinox in spring, on about March 20 in the northern hemisphere and September 22 in the southern hemisphere. Astronomy the equinox in March. Also called spring equinox. Astronomyanother term for First Point of Aries (see Aries).vernal equinox in other Oxford dictionaries Definition of vernal equinox in the British & World English dictionary
