P look-alike (3)
I believe the answer is:
rho
'p look-alike' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rho that I've seen before include "Something like 25 [ETA]" , "Sophocles character" , "letter to Athens" , "Greek character" , "Seventeenth letter of the Greek alphabet" .)