PUT UP OR SHUT UP

{v. phr.} {informal} 1. To bet your money on what you say or stop saying it. - Often used as a command; often considered rude. * /The man from out of town kept saying their team would beat ours and finally John told him "Put up or shut up."/ 2. To prove something or stop saying it. - Often used as a command; often considered rude. * /George told Al that he could run faster than the school champion and Al told George to put up or shut up./