Sailor taking favourite on ... explosive stuff! (9)
I believe the answer is:
saltpetre
'explosive stuff' is the definition.
The answer and definition can be both substances as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'sailor taking favourite on' is the wordplay.
'sailor' becomes 'salt' (salt is a kind of sailor).
'taking' is a charade indicator (letters next to each other).
'favourite' becomes 'pet' (synonyms).
'on' becomes 're' ('on' can be mean 'with reference to').
'salt'+'pet'+'re'='SALTPETRE'
Can you help me to learn more?
(Other definitions for saltpetre that I've seen before include "Component of gunpowder" , "explosive component" , "chemical" , "Gunpowder ingredient" , "Explosive ingredient" .)