What is a strong verb for smiled?

There isn't one single "strong" verb that perfectly replaces "smiled" because "smiled" is already a pretty strong verb, conveying happiness and positivity. However, depending on the context and nuance you want to convey, you could use verbs like:

For a more intense smile:

* Beamed

* Grinned

* Chortled (suggests a hearty, playful laugh)

* Guffawed (suggests loud laughter)

* Cackled (suggests a harsh, shrill laugh)

For a more subtle or enigmatic smile:

* Smirked (suggests knowingness or amusement)

* Glimmered (suggests a faint, but hopeful smile)

* Twinkled (suggests a playful or mischievous smile)

* Flashed (suggests a quick, bright smile)

For a more formal or polite smile:

* Graced (suggests a dignified smile)

* Courted (suggests a flirtatious smile)

* Illuminated (suggests a radiant smile)

Ultimately, the best "strong" verb will depend on the specific situation and the effect you want to achieve.