what a vengeance
Webster's Dictionary (GCIDE)
Vengeance \Venge"ance\, n. [F. vengeance, fr. venger to avenge, L. vindicare to lay claim to, defend, avenge, fr. vindex a claimant, defender, avenger, the first part of which is of uncertain origin, and the last part akin to dicere to say. See Diction, and cf. Avenge, Revenge, Vindicate.]
1.Punishment inflicted in return for an injury or an offense; retribution; -- often, in a bad sense, passionate or unrestrained revenge. [1913 Webster]
To me belongeth vengeance and recompense.— Deut. xxxii. 35.[1913 Webster]
To execute fierce vengeance on his foes.— Milton.[1913 Webster]
2.Harm; mischief. [Obs.] --Shak. [1913 Webster]
What a vengeance, or What the vengeance, what! -- emphatically. [Obs.] "But what a vengeance makes thee fly!" --Hudibras. "What the vengeance! Could he not speak 'em fair?" --Shak.
With a vengeance, (a) with great violence; as, to strike with a vengeance. [Colloq.] (b) with even greater intensity; as, to return one's insult with a vengeance. [1913 Webster + PJC]