WordWeb Online

1. Make a mock-up or prototype version of something
   "dummy up the books that are to be published"
   - dummy
    
2. [N. Amer] Refuse to talk or stop talking; fall silent
   "The children dummy up when their father approached"
   - close up, clam up, shut up, belt up, button up, be quiet, keep mum

Derived forms: dummied up, dummying up, dummies up

Type of: create, make, produce