A short, sudden intake of breath.

“The audience gave a gasp of astonishment”

: A draw or drag on a cigarette (or gasper).

“I'm popping out for a gasp.”

To draw in the breath suddenly, as if from a shock.

“The audience gasped as the magician disappeared.”

To breathe laboriously or convulsively.

“We were all gasping when we reached the summit.”

To speak in a breathless manner.

“The old man gasped his last few words.”

The sound of a gasp.

“Gasp! What will happen next?”