A term of general disgust, evolving over time from the original, " Eat Me ! ", because Mom didn't appreciate the brothers' emphatic expression of that phrase, thus it morphed into 'et ma', then 'ert ma' and finally, 'Utma ! ', still expressed emphatically to register ones disapproval or disgust over any number of daily situations. More recently, a Jewish variant has come into use, "Oytma !".
"Dude! I just sharted."
Ah, Utma, willya !?