Girl meets boy getting petrol (6)
I believe the answer is:
gallon
'petrol' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'girl meets boy' is the wordplay.
'girl' becomes 'gal'.
'meets' says to put letters next to each other.
'boy' becomes 'lon' ().
'gal'+'lon'='GALLON'
'getting' acts as a link.
Can you help me to learn more?
(Other definitions for gallon that I've seen before include "Liquid measure" , "Unit equal to 4 quarts" , "Eight pints or four quarts" , "8 pints (or ten in a hat!)" , "Unit of capacity" .)