On vacation, Ronnie Barker to make comeback? (5)
I believe the answer is:
recur
'make comeback?' is the definition.
(to recur is to appear or come up again)
'on vacation ronnie barker' is the wordplay.
'on vacation' says to hollow out the word (remove centre letters).
'barker' becomes 'cur' (cur can mean a dog, something which barks).
'ronnie' with its centre taken out is 're'.
're'+'cur'='RECUR'
'to' is the link.
(Other definitions for recur that I've seen before include "Perseverate" , "Happen repeatedly" , "Return to mind" , "Repeat" , "come back to one's mind" .)