Both the Duke and Duchess grinned broadly as they took turns at the wheel of the Sealegs, which reached speeds of 40 knots.
Asked whether he thought there might be some unofficial pinkwashing going on, he shrugged his shoulders and grinned.
When asked how he felt about the fact it made the possibility of him becoming king less likely, he grinned and said, "Great!"
Old English grennian "show the teeth" (in pain or anger), common Germanic (cf. 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.
1630s, from grin (v.).