Sailor robbed saint, reportedly — part of explosive mixture (9)
I believe the answer is:
saltpetre
'explosive mixture' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'sailor robbed saint reportedly part' is the wordplay.
'sailor' becomes 'salt' (salt is a kind of sailor).
'robbed saint reportedly' becomes 'pet' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'part' becomes 're' (re is a kind of part).
'salt'+'pet'+'re'='SALTPETRE'
'of' is the link.
Can you help me to learn more?
(Other definitions for saltpetre that I've seen before include "Compound" , "explosive component" , "chemical" , "Nitre" , "It's used as a fertilizer and explosive" .)