Liberal in overcoat embracing wife on a Cumbrian lake (9)
I believe the answer is:
ullswater
'a cumbrian lake' is the definition.
(I've seen this before)
'liberal in overcoat embracing wife on' is the wordplay.
'liberal' becomes 'l' (abbreviation).
'in' is an insertion indicator.
'overcoat' becomes 'ulster' (ulster is a kind of overcoat).
'embracing wife' becomes 'wa' (I can't justify this - if you can you should believe this answer much more).
'on' means one lot of letters goes inside another (as in clothing \'on\' a person).
'ulster' going around 'wa' is 'ulswater'.
'l' put into 'ulswater' is 'ULLSWATER'.
(Other definitions for ullswater that I've seen before include "Lake district lake" , "Mere" , "Cumbrian lake" .)