Spinner caught by posh Scotsman? Ideal! (7)
I believe the answer is:
utopian
'ideal' is the definition.
(similar in meaning)
'spinner caught by posh scotsman?' is the wordplay.
'spinner' becomes 'top' (a spinning top).
'caught by' means one lot of letters goes inside another.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'scotsman?' becomes 'Ian' (common Scottish name).
'u'+'ian'='uian'
'top' put within 'uian' is 'UTOPIAN'.
(Other definitions for utopian that I've seen before include "More work was literally so" , "Ideal; imaginary" , "Citizens of Thomas More's perfect country" , "Impractically idealistic" , "Of an ideal existence" .)