Where does “trioecious” come from?

trioecious (English) comes from English -oecious, from English -ous, from Middle English -ous, from Old French -us, from Latin -ōsus, from Old Latin -ōssus.

trioecious (English): Having male (staminate), female (pistillate), and bisexual flowers on the same plant (also known as "polygamous"), like Fraxinus excelsior

Definitions

Having male (staminate), female (pistillate), and bisexual flowers on the same plant (also known as "polygamous"), like Fraxinus excelsior

Ancestry of “trioecious”, step by step

Step	Language	Word	Meaning
1	English	-oecious	Forms adjectives describing the arrangement of...
2	English	-ous	Used to form adjectives from nouns, to denote...
3	Middle English	-ous	—
4	Old French	-us	-ous, used for forming adjectives
5	Latin	-ōsus	ose, -ous, -ful (full of or overly prone to)
6	Old Latin	-ōssus	—

Every word from Old Latin -ōssus →Every word from Latin -ōsus →Every word from English -ous →