|simpl. and trad.|
From 西 ("west") and 藏, the latter a transcription of Tibetan གཙང (gtsang, “a region in Tibet encompassing Gyantse and Shigatse”). Using this word to refer to Tibet in general was fairly recent [from 20th century]. The old Chinese words for Tibet were 蕃 and 吐蕃.
西藏 (traditional and simplified, Pinyin)