Tarzan says this all the time in movies and the original books. In the simple land of the jungle, there is apparently only use for one word. "Ungowa" is recited in numerous situations to many different effects. It calms animals. It calls animals to battle. It means "good". It means "bad". It means hello. It means goodbye. It basically means whatever Tarzan wants it to mean at any given moment. In that point it's quite the opposite of the eskimos' language. They have dozens of words for snow and Tarzan has one word for absolutely everything.