res judicata
Concise Oxford English Dictionary © 2008 Oxford University Press:
res judicata /reɪz ˌdʒuːdɪˈkɑːtə/
▶noun (pl. res judicatae /ˌdʒuːdɪˈkɑːtʌɪ, ˌdʒuːdɪˈkɑːtiː/) Law a matter that has been adjudicated by a competent court and may not be pursued further by the same parties.
– origin L., lit. ‘judged matter’.
'res judicata' also found in these Oxford entries:

