to tighten or fasten by knotting or anchoring a string, rope, belt or noose; compare buộc/cột (“to tie”, in general, loosely or tightly) and siết (“to tighten with a grip, stranglehold or chokehold”)

(literally) to tighten one's belt

(anatomy) the lower back / (chiefly Northern Vietnam, clothing) a belt

to tighten; to fasten; to stiffen / to strengthen; to reinforce (relations)

(medicine) spasm

(figurative, economics, government) to tighten one's belt, or more extremely, to be forced into austerity by the government