Reginald gets one of King Lear's daughters (5)
I believe the answer is:
regan
'one of king lear's daughters' is the definition.
(I've seen this in another clue)
'reginald gets' is the wordplay.
'reginald' becomes 'Reg' (short for Reginald).
'gets' becomes 'an' (I am not sure about this - if you are sure you should believe this answer much more).
'reg'+'an'='REGAN'
Can you help me to learn more?
(Other definitions for regan that I've seen before include "Work team" , "One of King Lear's daughters" , "Possessed gir" , "Shakespearean baddie" , "king's daughter" .)