Where does “cielarko” come from?

cielarko (Ido) comes from Ido arko, from Russian а́рка, from Italian arco, from Latin arcus, from Latin solium, from Proto-Indo-European sodyom, from Proto-Indo-European sḗd- — to sit.

cielarko (Ido): rainbow

Definitions

rainbow

Ancestry of “cielarko”, step by step

cielarko traces back through two separate lines of ancestry.

via Ido arko

Step	Language	Word	Meaning
1	Ido	arko	arch, arc; Alternative form of armarko
2	Russian	а́рка	arch, archway, arc
3	Italian	arco	bow; arc; arch
4	Latin	arcus	arc, arch; bow; rainbow
5	Latin	solium	seat, chair; throne, chair of state, official...
6	Proto-Indo-European	sodyom	—
7	Proto-Indo-European	sḗd-	to sit

via Ido cielo

Step	Language	Word	Meaning
1	Ido	cielo	sky; heaven
2	Esperanto	ĉielo	sky; heaven
3	Italian	cielo	sky; heaven
4	Latin	caelum	heaven; sky; atmosphere, climate, weather
5	Proto-Italic	kailom	sky
6	Proto-Indo-European	keh₂i-lom	whole
7	Proto-Indo-European	keh₂i-	—

Every word from Proto-Indo-European sḗd- →