grin

fe’l verb

1. To smile, parting the lips so as to show the teeth. Why do you grin?  Did I say something funny?
2. To express by grinning. She grinned pleasure at his embarrassment.
3. To grin as part of producing a particular facial expression, such as a smile or sneer. He grinned a broad smile when I told him the result.
4. To show the teeth, like a snarling dog.

ot noun

1. A smile in which the lips are parted to reveal the teeth.
2. A snare; a gin.