护照(hù zhào) - passport in Mandarin

护照 (hùzhào) is the passport, the document every traveller needs at border control. 护 (hù) means "to protect" and 照 (zhào) here means "licence, permit", so the compound reads roughly as "protection permit", the paper that vouches for you abroad.

It turns up constantly in travel and airport vocabulary: 出示护照 (chūshì hùzhào), "show your passport", is what you will hear at check-in and immigration, and 护照号码 (hùzhào hàomǎ) is your "passport number".

Watch the measure word: a single passport is 一本护照 (yì běn hùzhào), using 本 (běn), the measure word for bound, book-like things, not 个 (gè).