Guardian of Kings

Verzifier #3537

Last translation assistance request for a while, thanks to Ellanto for contributing to my understanding of Sindarin so far this Yule season. I read Gil-Galad was born Ereinion "Scion of Kings", and thought to use the plural "erein" = "kings" for something like Ereintir the "Kings Guard" or "Watcher of Kings".

Does that work in proper Sindarin(or even what we know of Noldorin) for a given name, or could you not shorten "tirith" which translates as "watcher, guard, protector to "tir" and use it as a suffix in Sindarin? Would that only work in Quenya as seen in Palantir? I've seen tirith and tir translated interchangeably into Sindarin/Noldorin but that could be due to old sources I'm just not sure.

Rínor #3538

The plural for king in Sindarin is Erain. Do to S35 "ai" can only exist in the the final syllable that is why it reverts to "ei" in the name. √TIR is “watch (over), look at, observe, gaze at”. Watch (over) the Kings should yield Ereithir IPA ɛ.rɛ͡ɪ.thir.

You could also do Tirerain IPA ti.rɛ.ra͡ɪn as well.