In LotR/IV:IV, Frodo is called Daur, which might be the mutated form of this word
Noldorin
tîr
adjective. straight, right
tîr
adjective. straight, right, straight, right; [G.] upright, honest; esteem, regard, honour
aran
noun. king (used of a lord or king of a specified region)
feir
noun. right (hand)
forgam
adjective. right-handed
forn
noun. right, north
fœir
noun. right (hand)
taer
adjective. straight
taer
adjective. straight
taur
noun. king (only used of the legitimate kings of whole tribes)
âr
noun. king (used of a lord or king of a specified region)
âr
noun. king
Written tær (with ae-ligature) in the Etymologies, rectified here according to VT/46:18 (which also lists the ligature)