Continental system that's taken English over, overnight (8)
I believe the answer is:
meteoric
'overnight' is the definition.
(thesaurus)
'continental system that's taken english over' is the wordplay.
'continental system' becomes 'metric' (I have seen 'System of measurement' mean 'metric' so perhaps 'system' could also mean 'metric'. I am not sure about the 'continental' bit.).
'that's taken' is an insertion indicator.
'english' becomes 'E' (abbreviation as in OED).
'over' becomes 'o' (cricket abbreviation).
'e'+'o'='eo'
'metric' placed around 'eo' is 'METEORIC'.
Can you help me to learn more?
(Other definitions for meteoric that I've seen before include "with brilliant speed" , "moving at high speed" , "Of a shooting star; remarkably fast" , "Dazzling, transient" , "Spectacular sort of rise" .)