Large lady's eating last of cake, a little down (7)
I believe the answer is:
feather
'a little down' is the definition.
'feather' can be an answer for 'down' (thesaurus). I'm unsure of the 'a little' bit.
'large lady's eating last of cake' is the wordplay.
'large' becomes 'fat' (I've seen this in other clues**).
'lady' becomes 'her' (I've seen this before).
'eating' means one lot of letters goes inside another.
'last of' suggests the final letters.
The final letter of 'cake' is 'e'.
'fat'+'her'='father'
'father' going around 'e' is 'FEATHER'.
(Other definitions for feather that I've seen before include "A white one denotes cowardice" , "trifling thing" , "The fear (anag) - type of bed" , "Quill" , "Part of covering of bird" .)