Someone who talks shit all the time to appear tough but never backs up their words or always comes up with an excuse.
all bark, no bite
Chiuaua Dude: "Man if that bich ass security guard bothers us ima shove that flashlight up his ass. H e better not even look over here
Security: "hey theres no loitering here, yall need 2 go"
Chiuaua dude: yes sir