We stand exposed, clutching the warning (6)
I believe the answer is:
beware
'warning' is the definition.
('beware!' might be shouted as a warning)
'we stand exposed clutching' is the wordplay.
'stand' says the letters should be written backwards (I've seen 'standing' mean this (in a down clue, letters stand up)).
'exposed' becomes 'bare' (I've seen this in another clue).
'clutching' indicates putting letters inside.
'we' in reverse letter order is 'ew'.
'ew' inserted into 'bare' is 'BEWARE'.
'the' acts as a link.
(Other definitions for beware that I've seen before include "Be alert for dangers" , "Steer clear of" , "Look out, take care" , "Cry of warning" , "Archaic warning to be careful, danger ahead" .)