Quenya name for the Grey Elves (PM/223), usually appearing in its plural form Sindar (LotR/1137). It is simply sinda “grey” used as a name (SA/thin(d)).
Quenya
Sindar
noun. Grey-elves
sinda
proper name. Grey-elf
sinda
adjective. grey
sindar eldar
Grey Elves
sindar eldaron
Grey Elves’
sindar i eldar malariando
Grey are the Elves of Beleriand
elwë, aran sindaron
Elwe, King of the Sindar
eldar sindar
Grey Elves
eldar sindaron
Grey Elves’
Grey-elves