Teller's partner in magic (4)
I believe the answer is:
penn
'teller's partner in magic' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for penn that I've seen before include "founder of colony" , "Milk actor" , "William --, founder of a US state" , "William ---, Quaker colonist" , "US state (abbrev.)" .)