Foreshadow a stupid speed (9)
I believe the answer is:
adumbrate
'foreshadow' is the definition.
(I've seen this before)
'a stupid speed' is the wordplay.
'stupid' becomes 'dumb' (similar in meaning).
'speed' becomes 'rate' (the speed at which something happens).
'a'+'dumb'+'rate'='ADUMBRATE'
(Other definitions for adumbrate that I've seen before include "Foreshadow with a drumbeat" , "sketch" , "Obscure" , "Indicate or describe in a general way" , "Depict in outline" .)