The term 'AMUSED REACTION' can be summarized by two crossword solutions, HAHA (4 letters) and LAUGH (5 letters). HAHA is an expression of amusement or joy, usually used in response to something funny. It is often used as an interjection to indicate laughter, and is also used as a verb to describe the act of laughing. LAUGH is an expression of mirth, amusement, or joy, typically resulting from something said or done that is found to be humorous or enjoyable. It is often used as an interjection to indicate laughter, and is also used as a verb to describe the act of laughing. Both HAHA and LAUGH are common expressions of amusement and joy, and are often used interchangeably.