Counterfeit, simulate (5)
I believe the answer is:
feign
I believe this clue is a double definition.
'counterfeit' is the first definition.
(I've seen this before)
'simulate' is the second definition.
(I know that simulate can be written as feign)
(Other definitions for feign that I've seen before include "Simulate, fake" , "Pretend, put on show of" , "Dissemble" , "Counterfeit, simulate" , "Pretend to experience" .)