Explicit about king with three daughters (5)
I believe the answer is:
clear
'explicit' is the definition.
(thesaurus)
'about king with three daughters' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'king with three daughters' becomes 'lear' (Shakespeare's King Lear).
'c'+'lear'='CLEAR'
(Other definitions for clear that I've seen before include "Unambiguous" , "Lucid, transparent" , "Acquit" , "Jump over without contact" , "Set free of charges" .)