Talented porter penning book (4)
I believe the answer is:
able
'talented' is the definition.
(I've seen this before)
'porter penning book' is the wordplay.
'porter' becomes 'ale' (I've seen this in other clues).
'penning' means one lot of letters goes inside another.
'book' becomes 'b'.
'ale' going around 'b' is 'ABLE'.
(Other definitions for able that I've seen before include "Competent as seaman may be" , "Bale out, being competent" , "As capable as a mariner" , "... was I ere I saw Elba (palindrome)" , "Having considerable skill" .)