Time for Beano editor to show up (3)
I believe the answer is:
eon
'time' is the definition.
(I've seen this before)
'beano editor to show up' is the wordplay.
'to show' indicates a hidden word.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'noe' is hidden within 'beano editor'.
'noe' back-to-front is 'EON'.
'for' is the link.
(Other definitions for eon that I've seen before include "Very long period (US and technical spelling)" , "Very long age" , "An immense time" , "In time, long division" , "Age, epoch" .)