noun.
A lawsuit filed against a party that has filed a suit against one.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a suit brought against someone who has sued you
Word Usage
"The legal team suing Chevron in Ecuador argued that the restraining order was unnecessary, given the absence of a verdict, and they called the countersuit a blatant attempt to bleed them of money."