Mistress Quickly's way to get fifty quid (4)
I believe the answer is:
nell
'mistress quickly's' is the definition.
(I've seen this in another clue)
'way to get fifty quid' is the wordplay.
'way' becomes 'n' (Compass direction - North).
'to get' means one lot of letters go next to another.
'fifty quid' becomes 'ell' (I can't justify this - if you can you should give a lot more credence to this answer).
'n'+'ell'='NELL'
Can you help me to learn more?
(Other definitions for nell that I've seen before include "Little -, (Dickens char.)" , "-- Gwyn, royal favourite" , "little Miss Trent?" , "Dickensian heroine" , "Little --; -- Gwyn" .)