GRINNING

smile, smiling, grin, grinning

(noun) a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

GRIN

grin

(verb) to draw back the lips and reveal the teeth, in a smile, grimace, or snarl

Source: WordNet® 3.1

Verb

grinning

present participle of grin

Noun

grinning (countable and uncountable, plural grinnings)

The act or expression of one who grins.

Source: Wiktionary

GRIN

Grin, n. Etym: [AS. grin.]

Definition: A snare; a gin. [Obs.] Like a bird that hasteth to his grin. Remedy of Love.

Grin, v. i. [imp. & p. p. Grinned; p. pr. & vb. n. Grinning.] Etym: [OE. grinnen, grennen, AS. grennian, Sw. grina; akin to D. grijnen, G. greinen, OHG. grinan, Dan. grine. Groan.]

1. To show the teeth, as a dog; to shsrl.

2. To set the teeth together and open the lips, or to open the mouth and withdraw the lips from the teeth, so as to show them, as in laughter, acorn, or pain. The pangs of death do make him grin. Shak.

Grin, v. t.

Definition: To express by grinning. Grinned horrible a ghastly smile.Milton.

Grin, n.

Definition: The act of closing the teeth and showing them, or of withdrawing the lips and showing the teeth; a hard, forced, or smeering smile. I.Watts. He showed twenty teeth at a grin. Addison.

Source: Webster’s Unabridged Dictionary 1913 Edition