Some; whichever (3)
I believe the answer is:
any
I believe this is a double definition.
'some' is the first definition.
(similar in meaning)
'whichever' is the second definition.
(I've seen this in another clue)
(Other definitions for any that I've seen before include "Several" , "One, no matter which" , "Some; none in particular" , "One or some, whichever you choose" , "Long-running Radio 4 discussion show" .)