Loathed revolutionary guards about to take off (6)
I believe the answer is:
detach
'take off' is the definition.
(I've seen this in another clue)
'loathed revolutionary guards about' is the wordplay.
'loathed' becomes 'hated' (I've seen this in another clue).
'revolutionary' says the letters should be written in reverse.
'guards' is an insertion indicator (inserted letters are guarded).
'about' becomes 'c' (abbreviation for circa).
'hated' written backwards gives 'detah'.
'detah' enclosing 'c' is 'DETACH'.
'to' is the link.
(Other definitions for detach that I've seen before include "Take away -- the cad (anag)" , "The reverse of 11 Down" , "Disengage, unfasten" , "free" , "Remove, cut out" .)