1786, Fig. 10. The spanner for spanning or winding up the spring of the wheel lock. — Francis Grose, A Treatise on Ancient Armour and Weapons, page xvi.
Naomi Wolf ’s The Beauty Myth was the first feminist treatise on women’s looks I didn’t find alienatingly hirsute.
Meaning of treatise for the defined word.
Grammatically, this word "treatise" is a noun, more specifically, a countable noun.