Difficult for daughters to exclude guest (4)
I believe the answer is:
hard
'difficult' is the definition.
(I know that difficult can be written as hard)
'daughters to exclude guest' is the wordplay.
'daughters' becomes 'd' (genealogical abbreviation for daughters).
'to' says to put letters next to each other (I've seen this in other clues).
'exclude guest' becomes 'har' (I am not sure about this - if you are sure you should believe this answer much more).
'd' put after 'har' is 'HARD'.
'for' is the link.
Can you help me to learn more?
(Other definitions for hard that I've seen before include "Complicated" , "Emergency lane" , "Resentment" , "Tough; rigid" , "Solid; difficult" .)