Where does “radiator” come from?

radiator (Portuguese) comes from Portuguese rádio, from New Latin radium, from French radium, from French radioactif, from French actif, from Old French actif, from Latin āctīvus, from Ancient Greek ἐνεργητικός — to carve, cut out with a knife, engrave; to note...

Ancestry of “radiator”, step by step

radiator traces back through two separate lines of ancestry.

via Portuguese rádio

Step	Language	Word	Meaning
1	Portuguese	rádio	radium; radio; radio station
2	New Latin	radium	radium; accusative singular of radius
3	French	radium	radium
4	French	radioactif	radioactive
5	French	actif	active; asset; top
6	Old French	actif	active
7	Latin	āctīvus	active
8	Ancient Greek	ἐνεργητικός	Able to act on; acting on; Active; In the active...
9	Ancient Greek	ἐνεργέω	to be in action or activity, to operate; to...
10	Ancient Greek	ἐνεργός	at work, active
11	Ancient Greek	ἐν-	in, within; on
12	Ancient Greek	ἐν	in, on, at; among; in, at, or during the time of
13	Ancient Greek	δέρμα	skin, hide
14	Ancient Greek	γλυφή	carving, carved work; hole cut
15	Ancient Greek	γλύφω	to carve, cut out with a knife, engrave; to note...

via Portuguese ator

Step	Language	Word	Meaning
1	Portuguese	ator	actor
2	Old Portuguese	abtor	—

Every word from Ancient Greek γλύφω →