Philosopher has time for item of jewellery (6)
I believe the answer is:
locket
'for item of jewellery' is the definition.
(I've seen this before)
'philosopher has time' is the wordplay.
'philosopher' becomes 'locke' (John Locke).
'has' says to put letters next to each other.
'time' becomes 't' (abbreviation).
'locke'+'t'='LOCKET'
(Other definitions for locket that I've seen before include "Small pendant containing photo" , "Small case on pendant, may hold photo" , "Lucy" , "Item of jewellery" , "Neck adornment" .)