Definition of "counterpunch"

A punch delivered in response to a previous punch by somebody else, such as an opponent in a boxing match.  examples

(printing, historical) A punch used in the cutting of other punches, often used to create the negative space in or around a glyph.

(boxing) To deliver a punch designed to exploit an opponent's momentary defensive weakness caused by a punch thrown by the opponent.  examples

To deliver a competitive response to an opponent designed to exploit a weakness created by the opponent's offensive efforts.  quotations  examples