Where does “cage” come from?

cage (Old French) comes from Latin cavea, from Latin cavus, from Proto-Italic kawos, from Proto-Indo-European ḱowh₁ós, from Proto-Indo-European ḱewh₁- — to swell; to be strong.

Ancestry of “cage”, step by step

Step	Language	Word	Meaning
1	Latin	cavea	hollow, cavity; cage, den, enclosure, stall,...
2	Latin	cavus	hollow, concave; excavated, channeled;...
3	Proto-Italic	kawos	—
4	Proto-Indo-European	ḱowh₁ós	hollow
5	Proto-Indo-European	ḱewh₁-	to swell; to be strong

Words derived from “cage”

cage
gage
birdcage
codger
kedge
cadge
cadger
cagelike
cageful
nanocage
encage
uncage
gager
cageless
cager
cagework
cagebird
cagemate
homecage
incage
cageling
codgerly
codgy
Gage

Every word from Proto-Indo-European ḱewh₁- →

cage — Etymology, Origin & Word History | Etymology Explorer