I. ˌē-kwə-ˈnäk-shəl, ˌe- adjective
Date: 1545
1. : relating to an equinox or to a state or the time of equal day and night
2. : relating to the regions or climate on or near the equator
3. : relating to the time when the sun passes an equinoctial point
II. noun
Date: 1521
1. : equator 1
2. : an equinoctial storm