Caution and worry after holiday is put back (6)
I believe the answer is:
caveat
'caution' is the definition.
(I know that caution can be written as caveat)
'worry after holiday is put back' is the wordplay.
'worry' becomes 'eat' (something worrying may eat someone up).
'after' is a charade indicator (letters next to each other).
'holiday' becomes 'vac' (abbreviation for vacation).
'is put back' says the letters should be written backwards.
'vac' reversed gives 'cav'.
'eat' put after 'cav' is 'CAVEAT'.
'and' acts as a link.
(Other definitions for caveat that I've seen before include "At cave (anag.)" , "Cautionary warning" , "Warning (of conditions)" , "'Warning, proviso (6)'" , "Vacate (anag) - warning" .)