Excellent suggestion given to Prince (6)
I believe the answer is:
tiptop
'excellent' is the definition.
(I've seen this before)
'suggestion given to prince' is the wordplay.
'suggestion' becomes 'tip' (tip is a kind of suggestion).
'given' says to put letters next to each other.
'prince' becomes 'p'.
'tip'+'to'+'p'='TIPTOP'
(Other definitions for tiptop that I've seen before include "Best of its kind" , "The very highest point" , "Informally excellent, very best" , "Excellent, super" , "The height of excellence" .)