Official drop before mum cuts great deal (8)
I believe the answer is:
diplomat
'official' is the definition.
(I know that diplomat is a type of official)
'drop before mum cuts great deal' is the wordplay.
'drop before' becomes 'dip' (I've seen this before. I am not sure about the 'before' bit.).
'mum' becomes 'ma' (both can mean mother).
'cuts' is an insertion indicator (some letters cut their way into a word).
'great deal' becomes 'lot' (both can mean a large amount).
'ma' placed into 'lot' is 'lomat'.
'dip'+'lomat'='DIPLOMAT'
Can you help me to learn more?
(Other definitions for diplomat that I've seen before include "eg Ambassador" , "tactful one" , "Official such as an ambassador" , "National representative abroad" , "Foreign representative" .)