Source : Webster's Revised Unabridged Dictionary (1913)

Chop suey \Chop su"ey\ or sooy \soo"y\ . [Chin. (Cantonese) shap
   sui odds and ends, fr. shap for sap to enter the mouth + sui
   small bits pounded fine.]
   A m['e]lange served in Chinese restaurants to be eaten with
   rice, noodles, etc. It consists typically of bean sprouts,
   onions, mushrooms, etc., and sliced meats, fried and flavored
   with sesame oil. [U. S.]

Source : WordNet®

chop suey
     n : meat or fish stir-fried with vegetables (e.g., celery,
         onions, peppers or bean sprouts) seasoned with ginger and
         garlic and soy sauce; served with rice; created in the
         United States and frequently served in Chinese
         restaurants there