Where does “firmamentum” come from?

firmamentum (Latin) comes from Latin firmō, from Latin Firmus, from Proto-Italic fermos, from Proto-Indo-European dʰer-mo-s, from Proto-Indo-European dʰer- — to support; to hold.

firmamentum (Latin): A strengthening, support, prop, stay; The...

Definitions

A strengthening, support, prop, stay; The...

Ancestry of “firmamentum”, step by step

firmamentum traces back through two separate lines of ancestry.

via Latin firmō

Step	Language	Word	Meaning
1	Latin	firmō	to make firm, strengthen, harden, fortify
2	Latin	Firmus	strong, powerful
3	Proto-Italic	fermos	—
4	Proto-Indo-European	dʰer-mo-s	holding
5	Proto-Indo-European	dʰer-	to support; to hold

via Ancient Greek στερέωμα

Step	Language	Word	Meaning
1	Ancient Greek	στερέωμα	foundation, framework, firmament
2	Ancient Greek	-μᾰ	"suffix forming a noun denoting the result of an...
3	Proto-Indo-European	-mn̥	Creates action nouns or result nouns from verbs

Words derived from “firmamentum”

Every word from Proto-Indo-European dʰer- →Every word from Proto-Indo-European dʰer-mo-s →Every word from Proto-Italic fermos →