Examine carefully for every purpose (6)
I believe the answer is:
peruse
'examine carefully' is the definition.
(I've seen this in another clue)
'every purpose' is the wordplay.
'every' becomes 'per' (I've seen this in other clues).
'purpose' becomes 'use' (synonyms).
'per'+'use'='PERUSE'
'for' acts as a link.
(Other definitions for peruse that I've seen before include "Read or study carefully" , "Read attentively" , "Scrutinise" , "'Read through, browse (6)'" , "Scan carefully for rupees" .)