guffaw
A loud, sudden, and very big burst of laughter.
A guffaw is a loud, unrestrained burst of laughter. It's the kind of laugh that erupts when something strikes you as so funny that you can't hold it back: a deep, hearty “HA HA HA!” that everyone in the room can hear. When your friend tells a joke that catches you completely off guard, you might let out a guffaw without meaning to.
The word captures both the sound and the feeling of uninhibited laughter. A guffaw isn't a polite chuckle or a quiet giggle. It's big, booming, and genuine. Picture a grandfather throwing his head back and guffawing at a silly pun, or a whole classroom guffawing when a science experiment goes hilariously wrong.
You can use guffaw as a verb too: “The audience guffawed at the comedian's stories.” While some situations call for restraint, a good guffaw shows that something truly delighted you. There's an honest, joyful quality to a guffaw that makes it contagious: when one person starts guffawing, others often join in.