Huge Tom runs so awkwardly (9)
I believe the answer is:
monstrous
'huge' is the definition.
(I've seen this before)
'tom runs so awkwardly' is the wordplay.
'awkwardly' is an anagram indicator.
'tom'+'runs'+'so'='tomrunsso'
'tomrunsso' with letters rearranged gives 'MONSTROUS'.
(Other definitions for monstrous that I've seen before include "Outrageously evil" , "Quite outrageous" , "Extraordinarily large" , "Outrageously wrong" , "Shockingly brutal or cruel" .)