Where does “gelidity” come from?

gelidity (English) comes from English gelid, from Latin gelidus, from Latin -idus, from Proto-Italic *-iðos.

gelidity (English): The state or quality of being gelid

Definitions

gelidity traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	English	gelid	Very cold; icy or frosty
2	Latin	gelidus	ice-cold, icy, frosty; chilling
3	Latin	-idus	tending to
4	Proto-Italic	*-iðos	—

Step	Language	Word	Meaning
1	English	ity	—
2	Ingrian	-u	Used to form nouns from verbs