ăn vụng 
to eat secretly, sneak food [ ăn ] : (1) to eat (away at), attack, corrode, cost; to attend, celebrate, take part in (a event where food is served); (3) to earn illegally
[ vụng ] : (1) on the sly, secretly; (2) unskilled, clumsy, awkward; (3) bay
Most Common Compounds Set 1:
Most Common Compounds Set 2 :
vụng ăn vụng nói to have trouble expressing oneself