Definition from Wiktionary, the free dictionary
nonagesimal (plural nonagesimals)
- (astronomy) The middle to highest point of a part of an ecliptic that is above the horizon at any period of time.
nonagesimal (not comparable)
- Of or relating to the ninetieth degree or to a nonagesimal.
- "nonagesimal": Collins English Dictionary - Complete & Unabridged 10th Edition. Article.