fake up
Advanced (C1)informal
To make something fake and pretend it is real.
"He faked up a medical certificate to explain his absence from work."
Hear it in context
"I feel like I've just destroyed evidence!"
Tom Scott · 3:21
Hold on, you have to fake up the blood in the way that reacts to test.
Joe Rogan Experience #2489 - Ryan Bingham
PowerfulJRE · 100:38
these are all fake up here and then my lip was just hanging by the thread.