Dessert - seconds accepted by timid type (6)
I believe the answer is:
mousse
'dessert' is the definition.
(mousse is a kind of dessert)
'seconds accepted by timid type' is the wordplay.
'seconds' becomes 's'.
'accepted by' indicates putting letters inside.
'timid type' becomes 'mouse' (I've seen this before).
's' going inside 'mouse' is 'MOUSSE'.
(Other definitions for mousse that I've seen before include "Shock treatment" , "Frothy creamy substance for styling hair" , "Something for the hair" , "Whipped savoury dish" , "Frothy dish - hairdressing" .)