Charlie conceals rebukes (6)
I believe the answer is:
chides
'rebukes' is the definition.
(I know this)
'charlie conceals' is the wordplay.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'conceals' becomes 'hides' ('hide' can be a synonym of 'conceal').
'c'+'hides'='CHIDES'
(Other definitions for chides that I've seen before include "Censures severely or angrily" , "Admonishes, rebukes" , "Scolds, rebukes" , "Admonishes, reproves" , "Admonishes, scolds" .)