Is it res judicata? (lawyer lingo)

 
Yes, it's Latin, and it is an affirmative defense that may thwart a (second) lawsuit.  
  
RES JUDICATA  
  
Res judicata prevents parties and those in privity with them from relitigating a case that a competent tribunal has adjudicated to finality. Ingersoll–Rand Co. v. Valero Energy Corp., 997 S.W.2d 203, 206 (Tex. 1999).

Res judicata bars claims or defenses that could have been litigated in the earlier suit but were not. Id. at 206–07. “The doctrine is intended to prevent causes of action from being split, thus curbing vexatious litigation and promoting judicial economy.” Id. at 207.

Under the doctrine of res judicata, a party is precluded from litigating a claim in a pending action if: (1) in a previous action, a court of competent jurisdiction rendered a final determination on the merits of a claim; (2) the parties that litigated the prior claim are identical to or in privity with the parties litigating the pending claim; and (3) the pending claim (a) is identical to the prior claim or (b) arises out of the same subject matter as the prior claim and could have been litigated in the previous action. Travelers Ins. Co. v. Joachim, 315 S.W.3d 860, 862 (Tex. 2010); Amstadt v. U.S. Brass Corp., 919 S.W.2d 644, 652 (Tex. 1996).
 
SOURCE: HOUSTON COURT OF APPEALS - 01-10-01151-CV - 12/14/11