Left under wraps, cry out (6)
I believe the answer is:
bellow
'cry out' is the definition.
(thesaurus)
'left under wraps' is the wordplay.
'left' becomes 'l' (common abbreviation).
'under' becomes 'below' (synonyms).
'wraps' indicates putting letters inside (inserted letters get wrapped up).
'l' put within 'below' is 'BELLOW'.
(Other definitions for bellow that I've seen before include "Roar like a bull" , "Loud cry of a bull" , "Loud deep sound as by bull" , "Shout; Saul --, novelist" , "Roar loudly" .)