Verb has 2 senses

• dummy up(v = verb.creation) dummy - make a dummy of; "dummy up the books that are to be published"

Sample sentence:
Somebody ----s something

• dummy up(v = verb.communication) be quiet, belt up, button up, clam up, close up, keep mum, shut up - refuse to talk or stop talking; fall silent; "The children shut up when their father approached"
Sample sentence:
Somebody ----s