To say something in a hissing manner, as through one's clenched teeth, typically due to anger. A noun or pronoun can be used between "hiss" and "out." Mom hissed out a command to be quiet as everyone in church turned around to look at Tommy and me.
hiss something out
Fig. to say something with a hissing voice, usually in anger or disgust. The disgusted manager hissed his appraisal out. He hissed out his criticism.