Lincoln in-law (4)
I believe the answer is:
todd
'lincoln in-law' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for todd that I've seen before include "Irish-born British actor and soldier, Richard, d. 2009" , "Richard --, was Guy Gibson in The Dam Busters" , "19th-century demon barber of Fleet Street" , "Sweeney, Fleet Street barber" , "Demon 12 of Fleet Street" .)