to put down or undermine someone or their efforts, the opposite of "
pump up"
also, to psych out somebody in a
negative way
chump down:
"to hell with what they say man....don't ever let anyone
chump you down, I know you can pull this off!"
"look man, I know I can
chump this guy down...just give me a shot, I know I can get him to fess up!"