res ju·di·ca·ta 
(rēz′ j′dĭ-kätə, rās′)
(rēz′ j′dĭ-kätə, rās′)n. pl. res ju·di·ca·tae (-kätē, -tī)
1. The principle that a decision by a competent court in a case fully and fairly litigated is final and conclusive as to the claims and issues of the parties and cannot be relitigated.
2. A claim or issue that has been decided under this principle.
[Latin rēs iūdicāta, thing decided : rēs, thing + iūdicāta, feminine past participle of iūdicāre, to judge.]