Where does “rhennagh” come from?

rhennagh (Manx) comes from Old Irish raithnech, from Proto-Celtic ɸratinākā, from Proto-Celtic ɸratis, from Proto-Indo-European p(t)erH- — fern.

rhennagh (Manx): fern

Definitions

Step	Language	Word	Meaning
1	Old Irish	raithnech	fern, bracken
2	Proto-Celtic	ɸratinākā	—
3	Proto-Celtic	ɸratis	fern
4	Proto-Indo-European	p(t)erH-	fern

rhennagh — Etymology, Origin & Word History | Etymology Explorer