Where does “geada” come from?

geada (Old Portuguese) comes from Latin gelāta, from Latin gelō, from Latin -ō, from Proto-Indo-European -ō — Derives nouns from roots.

Ancestry of “geada”, step by step

Step	Language	Word	Meaning
1	Latin	gelāta	frost
2	Latin	gelō	—
3	Latin	-ō	suffixed to nouns or adjectives. Originally a-stem nouns. Later extended to nouns with other stems. Forms regular first-conjugation verbs
4	Proto-Indo-European	-ō	Derives nouns from roots