Feigning; performing (6)
I believe the answer is:
acting
I believe this clue is a double definition.
'feigning' is the first definition.
(I've seen this before)
'performing' is the second definition.
(acting is a kind of performing)
(Other definitions for acting that I've seen before include "Feigning" , "Temporary - work in the theatre" , "Performing on stage" , "Playing a part" , "Filling a role on a temporary basis" .)