Take stock when philosopher overheard? (6)
I believe the answer is:
rustle
'take stock' is the definition.
(rustle can mean to steal cattle or stock)
'philosopher overheard?' is the wordplay.
'philosopher' becomes 'russell' (Bertrand Russell).
'overheard?' shows a homophone (sound like).
'russell' is a homophone of 'RUSTLE'.
'when' acts as a link.
(Other definitions for rustle that I've seen before include "Steal ((eg, cattle)" , "Steal cattle or livestock with whispering sound" , "Steal livestock - make a little noise" , "Dry crackling sound" , "Make sound as of paper crumpling - or steal cattle" .)