Where does “daa-heedragh” come from?

daa-heedragh (Manx) comes from Manx daa-, from Manx daa, from Old Irish dá, from Proto-Celtic dwau, from Proto-Brythonic dọw, from Proto-Celtic *duwo, from Proto-Indo-European dwóh₁ — two.

daa-heedragh (Manx): dihedral

Definitions

dihedral

Ancestry of “daa-heedragh”, step by step

Step	Language	Word	Meaning
1	Manx	daa-	di-, bi-, two-, ambi-, double-
2	Manx	daa	two
3	Old Irish	dá	two
4	Proto-Celtic	dwau	two
5	Proto-Brythonic	dọw	two
6	Proto-Celtic	*duwo	two
7	Proto-Indo-European	dwóh₁	two

Every word from Proto-Indo-European dwóh₁ →Every word from Proto-Celtic *duwo →Every word from Proto-Brythonic dọw →