Alongside this female comedian -- what about that? (8)
I believe the answer is:
herewith
'alongside' is the definition.
Both the answer and definition are adverbs. Maybe there's an association between them I don't understand?
'this female comedian what about that?' is the wordplay.
'this female' becomes 'her' (I've seen this before).
'comedian' becomes 'wit' (a witty person).
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
'about that?' means one lot of letters goes inside another.
'wit' put inside 'eh' is 'ewith'.
'her'+'ewith'='HEREWITH'
Can you help me to learn more?
(Other definitions for herewith that I've seen before include "Accompanying this (letter)" , "Attached or enclosed" , "Along with this letter" .)