[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./