Wise people round learner driver cutting speeds (7)
I believe the answer is:
oracles
'wise people' is the definition.
(oracle can humorously mean a wise person)
'round learner driver cutting speeds' is the wordplay.
'round' becomes 'o' (round can mean a round object).
'learner driver' becomes 'l' (learner drivers have L-plates on their cars).
'cutting' means one lot of letters goes inside another (some letters cut their way into a word).
'speeds' becomes 'races' ('race' can be a synonym of 'speed').
'l' put into 'races' is 'racles'.
'o'+'racles'='ORACLES'
(Other definitions for oracles that I've seen before include "Prophets, seers" , "They were consulted by ancient Greeks" , "Solacer for wise or knowledgeable people" , "Places where ancient Greek consulted their gods" , "Prophetic authorities" .)