The term SILLY SMILE is composed of two crossword solutions, SIMPER (6 letters) and GRIN (4 letters). A SIMPER is a facial expression that is a combination of a smile and a smirk, often used to convey coyness or flirtatiousness. A GRIN, on the other hand, is a broad smile that is usually used to express amusement or pleasure. Together, these two expressions form a silly smile, which is often used to show joy or amusement in a lighthearted way.