Just this writer embraces the Queen (4)
I believe the answer is:
mere
'just' is the definition.
(I've seen this in other clues)
'this writer embraces the queen' is the wordplay.
'this writer' becomes 'me' (the person who wrote the clues).
'embraces' means one lot of letters goes inside another.
'the queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'me' placed around 'er' is 'MERE'.
(Other definitions for mere that I've seen before include "See 13" , "Just an English lake" , "Pond - pure and simple" , "sea" , "Bare, simple" .)