gan vàng dạ sắt 
faithful, loyal, constant, as constant as [ gan ] : (1) liver; brave, courageous, tough; (2) palm (of hand), sole (of foot)
[ vàng ] : gold, yellow
[ dạ ] : (1) polite yes, (introductory word of respect), OK; (2) stomach, abdomen, heart, feeling; (3) night
[ sắt ] : iron
Most Common Compounds Set 1:
Most Common Compounds Set 2 :