Inventor with unit in institute's lab (5)
I believe the answer is:
tesla
'inventor' is the definition.
(I've seen this before)
'unit in institute's lab' is the wordplay.
'unit in' says the answer is hidden in the clue.
'TESLA' is hidden in the letters of 'institutes lab'.
'with' acts as a link.
(Other definitions for tesla that I've seen before include "Inventive sort" , "electrical unit" , "Physicist" , "American scientist" , "Physics unit" .)