a Roland for an Oliver

Etymology
From the stories of Roland and Oliver, legendary knights of equal might.

Noun

 * 1)  Equal measure; measure for measure; adequate response.

Adverb

 * 1)  Used to indicate that something is done in a manner that responds to an action with an equivalent action; tit for tat.
 * 2) * He responded to the insult a Roland for an Oliver, striking back just as hard.