Idealistic Scotsman follows upper-class head (7)
I believe the answer is:
utopian
'idealistic' is the definition.
('utopian' can be similar in meaning to 'idealistic')
'scotsman follows upper-class head' is the wordplay.
'scotsman' becomes 'ian'.
'follows' says to put letters next to each other.
'upper-class' becomes 'u' ('u' can be similar in meaning to 'upper-class').
'head' becomes 'top' ('top' can be a synonym of 'head'**).
'u'+'top'='utop'
'ian' after 'utop' is 'UTOPIAN'.
(Other definitions for utopian that I've seen before include "in a dreamy state" , "Idealistic reformer" , "Fancifully ideal" , "Too perfect for this world" , "Perfectionist reformer" .)