Firstly elicit admission, then scoff (3)
I believe the answer is:
eat
'scoff' is the definition.
(to scoff something is to eat it quickly)
'firstly elicit admission then' is the wordplay.
'firstly' indicates taking the first letters.
The first letters of 'elicit admission then' is 'EAT'.
(Other definitions for eat that I've seen before include "Feed" , "Bite, chew and swallow" , "get stuck in" , "Be corrosive" , "tolerate in diet" .)