tủ

Etymology 1
Perhaps. Compare 🇨🇬, 🇨🇬, 🇨🇬.

Noun

 * 1) cabinet; cupboard; wardrobe; chest; safe
 * 2)  something valuable and useful that is kept by people to themselves, and only shown or used in times of need to win over others; stock-in-trade
 * 3)  part of a subject deemed to be high-yield in exams and chosen as the focus of one's study/exam preparation

Verb

 * 1)  to cover (with); to overlay (with)