Literal:
* The embers in the fireplace smoldered, slowly releasing a warm glow.
* The burnt-out match smoldered on the floor, a tiny wisp of smoke rising into the air.
Figurative:
* After the argument, she smoldered with anger, refusing to speak to him.
* The detective smoldered with suspicion, watching the suspect closely.
* His resentment smoldered beneath the surface, occasionally bursting into a heated outburst.
* The city smoldered in the aftermath of the riot, the air thick with the smell of smoke and tension.
Note: "Smolder" can also be used as a verb meaning "to burn slowly without a flame."
Let me know if you'd like more examples or have any other questions!