Eat with Queen? Fantastic! (5)
I believe the answer is:
super
'fantastic' is the definition.
(I've seen this before)
'eat with queen?' is the wordplay.
'eat' becomes 'sup' (supping is a kind of eating).
'with' means one lot of letters go next to another.
'queen?' becomes 'er' (abbreviation for Elizabeth Regina).
'sup'+'er'='SUPER'
(Other definitions for super that I've seen before include "Delightful" , "(Of product) of extra fine quality" , "Great; wonderful" , "Excellent; police officer" , "Exceptional" .)