Skip some testimonial review (4)
I believe the answer is:
omit
'skip' is the definition.
(I know that skip is a more specific form of omit)
'some testimonial review' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'review' shows that the letters should be reversed in order.
'timo' is hidden in the letters of 'testimonial'.
'timo' reversed gives 'OMIT'.
(Other definitions for omit that I've seen before include "Leave out or overlook" , "Drop" , "Leave out or forget" , "Skip" , "Fail to use" .)