countersue


coun·ter·sue

C0690500 (koun′tər-so͞o′)tr.v. coun·ter·sued, coun·ter·su·ing, coun·ter·sues Law To respond to a lawsuit against oneself by suing (the plaintiff).
coun′ter·suit′ (-so͞ot′) n.

countersue

(ˈkaʊntəˌsuː) vb (tr) (Law) law to sue (a plaintiff) in response or opposition to a preceding lawsuit