What is the opposite of a Pyrrhic victory?

Answer 1

Since a Pyrrhic victory is defined as a "victory with devastating cost to the victor", the opposite can either of two things; "a loss with devastating cost to the victor" (in which the perspective is opposed to the Pyrrhic Victory) or "a victory with devastating cost to the loser".

In the case of the former, one could say that this is exactly the same as a Pyrrhic victory, but seen from the losing side. This is comparable to a 'heroic failure'.

In the case of the latter, one could say this is a 'massacre', in which the victor sustains no significant loss, but the losing side taking massive losses.