Where does “estromal” come from?

estromal (Spanish) comes from Spanish estroma, from Latin strōma, from Ancient Greek στρῶμα, from Proto-Hellenic strṓmə, from Proto-Indo-European sterh₃-, from Proto-Indo-European ster- — sterile, infertile.

estromal (Spanish): stroma; stromal of or relating to a stroma

Definitions

stroma; stromal of or relating to a stroma

Ancestry of “estromal”, step by step

Step	Language	Word	Meaning
1	Spanish	estroma	stroma
2	Latin	strōma	blanket; bedcover; coverlet
3	Ancient Greek	στρῶμα	mattress, bed; bedclothes; horsecloth
4	Proto-Hellenic	strṓmə	—
5	Proto-Indo-European	sterh₃-	to spread, extend, stretch out
6	Proto-Indo-European	ster-	sterile, infertile

Every word from Proto-Indo-European ster- →Every word from Proto-Indo-European sterh₃- →Every word from Proto-Hellenic strṓmə →