dummy up

1. 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.

   make a dummy of

3. (imperative, разговорное, иногда)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.

   refuse to talk or stop talking; fall silent

неправильный

• dummy upTo make a mock-up or prototype version of something, without some or all off its intended functionality.
• dummy outTo remove (a feature, subplot, item, or character) from a video game.