Grin
来自Big Physics
Old English grennian ‘bare the teeth in pain or anger’, of Germanic origin; probably related to groan.
wiktionary
Before 1000 CE - From Middle English grinnen, from Old English grennian, of Germanic origin and probably related to groan. Compare to Old High German grennan(“to mutter”)
From Old English grin
etymonline
grin (v.)
Old English grennian "show the teeth" (in pain or anger), common Germanic (cognates: Old Norse grenja "to howl," grina "to grin;" Dutch grienen "to whine;" German greinen "to cry"), from PIE root *ghrei- "be open." Sense of "bare the teeth in a broad smile" is late 15c., perhaps via the notion of "forced or unnatural smile." Related: Grinned; grinning.
grin (n.)
1630s, from grin (v.).
