Speaker's gift Gladstone perhaps brought back? (3)
I believe the answer is:
gab
'speaker's gift' is the definition.
(I've seen this in other clues)
'gladstone perhaps brought back?' is the wordplay.
'gladstone perhaps' becomes 'bag' (gladstone is a kind of bag).
'brought back?' is a reversal indicator (I've seen 'bring back' mean this).
'bag' reversed gives 'GAB'.
(Other definitions for gab that I've seen before include "Natter" , "Talk at length, chatter" , "Talk, chatter (colloq.)" , "The Irish are said to have the gift of it" , "Loquacity the gift of it" .)