Quenya 

-tar

king

-tar or tar-, element meaning "king" or "queen" in compounds and names (TĀ/TA3), e.g. Valatar; compare the independent nouns tár, tári. Prefix Tar- especially in the names of the Kings and Queens of Númenor (e.g. Tar-Amandil); see their individual names (like Amandil in this case), cf. also Tar-Mairon "King Excellent", title used by Sauron (PE17:183). Also in Tareldar "High-elves"; see also Tarmenel.