The term 'Amused Expression' can be expressed in three different ways: GRIN (4 letters), HEH (3 letters), and HAHA (4 letters). A GRIN is a facial expression that typically involves both the mouth and eyes, and is often used to express amusement or pleasure. HEH is an informal expression of laughter, usually used to indicate mild amusement. Finally, HAHA is a more intense expression of laughter, indicating strong amusement or joy.