The term 'evil grin' can be described by two crossword solutions: LEER (4 letters) and SNEER (5 letters). A LEER is a facial expression that is often seen as sly or mischievous, usually involving a sideways glance with a smirk or half-smile. A SNEER is a facial expression of contempt or scorn, often accompanied by a curled lip. Both expressions are associated with an evil grin, which is a malicious smile that conveys a feeling of superiority or pleasure in someone else's misfortune.