hiss / his/ • v. [intr.] make a sharp sibilant sound as of the letter s: the escaping gas was now hissing. ∎ (of a person) make such a sound as a sign of disapproval or derision: the audience hissed loudly at the mention of his name. ∎ [tr.] express disapproval of (someone) by making such a sound: he was hissed off the stage. ∎ whisper something in an urgent or angry way: he hissed at them to be quiet | [with direct speech] “Get back!” he hissed. • n. a sharp sibilant sound: the spit and hiss of a cornered cat. ∎ a sound such as this used as an expression of disapproval or derision: a hiss of annoyance. ∎ electrical interference at audio frequencies: tape hiss.