Philanderer about to embrace a king (4)
I believe the answer is:
rake
'philanderer' is the definition.
(thesaurus)
'about to embrace a king' is the wordplay.
'about' becomes 're' (regarding**).
'to embrace' means one lot of letters goes inside another.
'king' becomes 'k'.
'a'+'k'='ak'
're' placed around 'ak' is 'RAKE'.
(Other definitions for rake that I've seen before include "Progress was visualised for one" , "Smooth - Lothario" , "Garden tool with prongs" , "this to smooth the way?" , "disreputable fellow" .)