Do likewise (6,4)
'do likewise' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for imitate that I've seen before include "Copy, simulate" , "Copy someone" , "Copy or mimic" , "Mock" , "Mimic or follow as a model" .)
(Other definitions for follow suit that I've seen before include "Play another club, perhaps" , "go from club to club" , "Do the same as someone else" , "in due course" , "Be guided by corporation man" .)