chí thành 
sincere, frank, candid, open-hearted [ chí ] : (1) will, volition; (2) to, up to
[ thành ] : (1) citadel, fortress, wall; (2) to, into; (3) to succeed; (4) to become; (5) honest, sincere
Most Common Compounds Set 1:
Most Common Compounds Set 2 :