Warning, caution (6)
I believe the answer is:
I believe this clue is a double definition.
'warning' is the first definition.
(I know that caveat is a type of warning)
'caution' is the second definition.
(I know that caution can be written as caveat)
(Other definitions for caveat that I've seen before include "A warning against certain acts" , "Let the buyer beware ...emptor" , "'Warning, proviso (6)'" , "At cave (anag.)" , "Formal warning" .)