dummy up
verb1
To make a mock-up or prototype version of something, without some or all off its intended functionality.
- The carpenters dummied up a set of simple props for the rehearsals.
2
To make a fake version of something; to make a counterfeit.
3
Imperative, Informal, Sometimes To suddenly stop talking; shut up; to keep a secret; to refuse to talk.
- When he couldn't think of any more good lies, he just dummied up.
- Everyone was discussing the new teacher, but when she entered the room they all dummied up.