Tibet

Of unclear origin, but probably from Old Turkic 𐱅𐰇𐰯𐰇𐱅 (Töpüt) ('hilly, mountainous place') via Classical Persian تبت (tabbat, tubbat). In one proposed etymology the ultimate origin is Tibetan བོད (Bod), used in the compound name Tibetan སྟོད་བོད (stod bod, “Upper Tibet”), pronounced Tö-pöt, from སྟོད (stod, “upper, higher”) +‎ བོད (bod, “Tibet”).

In another proposal, the name comes via Classical Mongolian [script needed] (Töpüt) from an alteration of Old Turkic 𐱅𐰇𐰯𐰇 (töpü, “height, summit”).

Bialek instead derives the name from Old Tibetan དཔོན (dpon, “leader, ruler”) +‎ Old Turkic -𐱅 (-t²) plural suffix and a epenthetic vowel to break up the non-Turkic initial consonant cluster [tp]; according to her, Middle Chinese 吐蕃 (thuX bjon) comes from the same source.