Fellow to turn to the Spanish petrol (4)
I believe the answer is:
fuel
'petrol' 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?
'fellow to turn to the spanish' is the wordplay.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'to turn' becomes 'U' (a 'U-turn' is a kind of turn).
'to the spanish' becomes 'el' ('the' in Spanish).
'f'+'u'+'el'='FUEL'
Can you help me to learn more?
(Other definitions for fuel that I've seen before include "Eg, coal or oil" , "coal etc" , "Power source; inflame" , "Material for burning" , "Eg, coal or petrol" .)