She'll always give a chap a light (5)
I believe the answer is:
vesta
'chap a light' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'she'll always give a' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
The remaining letters 'vest' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for vesta that I've seen before include "Asteroid; goddess; match" , "Stave (anag.)" , "Hearth goddess; a match" , "Roman goddess; match" , "Roman goddess of the hearth" .)