1. A person, namely a male, who talks a big game but has none whatsoever. This individual goes to the gym but only to leer at others working out.
2. The biggest of all the chumps.
Two of Mike's friends get into a fight. Mike hides under the table in the fetal position...The next day at the gym Mike has the audacity to say he didn't want to jump in because he is too big. Everyone agrees that Mike is a true Chumpzilla.