Expertise in speech-making? Not at all (5)
I believe the answer is:
nohow
'at all' is the definition.
(thesaurus)
'expertise in speech' is the wordplay.
'expertise' becomes 'knowhow' (I've seen this before).
'in speech' indicates a 'sounds like' (homophone) clue.
'knowhow' is a homophone of 'NOHOW'.
'making? not' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for nohow that I've seen before include "not at all the American way?" , "Absolutely not in America" , "Never" , "Under no circumstances (as Tweedledum said)" , "Not at all in US" .)