Some Clint Eastwood number (3)
I believe the answer is:
two
'number' is the definition.
(I know that two is a Perrin number)
'some clint eastwood' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'TWO' is hidden in the letters of 'clint eastwood'.
(Other definitions for two that I've seen before include "Company, so it's said" , "Fifth root of thirty-two" , "Pair, deuce" , "Number of faces of the god Janus" , "Company allegedly" .)