It may be obtained from the girl at the tobacconist's (7)
I believe the answer is:
lighter
'the tobacconist's' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'it may be obtained from the girl' is the wordplay.
'the girl' can be anagrammed to 'LIGHTER'.
But, I am unsure how this is indicated.
'at' is the link.
Can you help me to learn more?
(Other definitions for lighter that I've seen before include "Boat for heavy loads and fire igniter" , "carrying less weight" , "Barge - less heavy" , "craft" , "Flat-bottomed barge - not so heavy" .)