hoàn toàn bất ngờ 
completely unexpected [ hoàn ] : to return
[ toàn ] : all, entire, whole
[ bất ] : (1) not, non-, un-; (2) type of card game
[ ngờ ] : to suspect, doubt
Most Common Compounds Set 1:
Most Common Compounds Set 2 :
hoàn toàn bất ngờ completely unexpected