A spasm of the diaphragm, or the resulting sound.
There was a loud hiccup from the back of the room and the class erupted in laughter.
(by extension) Any spasm or sudden change.
A minor setback.
There's been a slight hiccup in the processing of this quarter's results.
To produce a hiccup; have the hiccups.
To say with a hiccup.
"I haven't touched a drop, officer," the suspect hiccupped.
To produce an abortive sound like a hiccup.
The car engine hiccupped but wouldn't start.