Tesla is not corrupt (5)
I believe the answer is:
taint
'corrupt' is the definition.
(synonyms)
'tesla is not' is the wordplay.
'tesla' becomes 'T' (scientific unit).
'is not' becomes 'aint' (I've seen this in other clues).
't'+'aint'='TAINT'
(Other definitions for taint that I've seen before include "Adulterate" , "Defile" , "Blemish" , "Contaminating influence" , "soil" .)