More generally, an impulse response refers to the reaction of any dynamic system in response to some external change.

The name originally given to this complex refers to the reaction erythrocytes gave to the standard Miltenberger antisera used to test them.

"They think it's odd," he said, referring to the reaction of his class that he would be teaching in the United States.

Ground itch refers to the inflammatory reaction resulting from certain helminthic invasions into the skin.

"I cannot say they have accepted it," the Mayor said, referring to the reaction of state officials with whom his proposal had been discussed.

Emotion, in psychology and common use, refers to the complex reaction of an organism to significant objects or events, with subjective, behavioral, physiological elements.

"I heard a scream from the back room," Jagr said, referring to the reaction of teammates.

"I don't know what they're going to do," he said, referring to the public reaction.

Mrs Wallis has already referred to the reaction in the United Kingdom, for example.

"This is going to ring bells," a State Department official said, referring to the likely reaction by Hamas.