Freely confess: 'Ridiculous bonus over short time' (7)
I believe the answer is:
unbosom
'freely confess' is the definition.
(as in unbosoming yourself to someone)
'ridiculous bonus over short time' is the wordplay.
'ridiculous' indicates an anagram.
'over' shows that the letters should be reversed in order.
'short time' becomes 'mo' (as in 'just a mo').
'mo' backwards is 'om'.
'bonus' anagrammed gives 'unbos'.
'unbos'+'om'='UNBOSOM'
(Other definitions for unbosom that I've seen before include "Relieve oneself (of troubling information)" , "Reveal thoughts - get them off your chest" .)