chuckled
v. B2 Upper Intermediate US //ˈtʃəkəɫd// UK //tʃˈʌkəld// chuck·led
v. laughed quietly or to yourself, often because you found something funny or clever.
v. laughed in a quiet, suppressed manner, often expressive of internal amusement or satisfaction. The past tense of 'chuckle'.
He chuckled at the joke in the newspaper.
She chuckled softly to herself as she remembered the funny look on his face during the meeting.
The professor chuckled at the student's witty observation, acknowledging the cleverness of the remark without disrupting the quiet atmosphere of the library.
Usage
The verb is intransitive but often takes the preposition 'at' followed by the source of amusement.