Philly ivy (4)
I believe the answer is:
penn
'philly ivy' 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 "William ---, Quaker colonist" , "US state (abbrev.)" , "Milk actor" , "Colonising Quaker" , "founder of colony" .)