According to my Webster's New World Dictionary, equinox [ee-kwuh-noks] is a noun that means "the time when the sun crosses the equator, making night and day of equal length in all parts of the earth: the vernal (or spring) equinox occurs about March 20, the autumnal equinox about September 22." Yes, that means that the autumnal equinox is coming up soon, and then it will officially be fall! Here are a few sentences I came up with using our word of the week:
My daughter was born on the vernal equinox.
I love most things about autumn,
but I don't like how it starts
getting dark earlier after the equinox.
Some people hold religious celebrations
or festivals on the equinox.