Latin. Of its (his, her, their) own accord. This term refers to action taken by a court without being asked to do so by a party, e.g., The court dismissed the claim sua sponte.
Occasionally pronounced (at least by lawyers at my old firm) as "sua spumoni," which of course means "of his own Italian ice cream." Which reminds me, National Spumoni Day is coming up soon -- August 21!