One Who Overpowers His Speech is Called “a Man”:

The pasuk states (Tehillim 34:13): "Who is the man who desires life, who loves days to see good..." Sefer Reishis Chochmah (Shaar Hakedusha, Perek 11) notes that the Zohar Hakadosh (Parshas Terumah 158A) writes that one who overcomes his yeitzer hara is called "ish" (a man). So why is a man who guards his words called an "ish"? Because the temptation for the sins of the tongue is constant and it takes a lot of strength to overcome it. Thus, one who finds the inner fortitude to do this is certainly worthy of being called “a man”.