Where does “pyromorphous” come from?

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

pyromorphous (English): changing form when heated, especially forming...

Definitions

changing form when heated, especially forming...

Ancestry of “pyromorphous”, step by step

Step	Language	Word	Meaning
1	English	-morphous	having a specified shape or form
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 →