Mean to follow this middle course (6)
I believe the answer is:
golden
'mean' is the definition.
(thesaurus)
'follow this middle course' is the wordplay.
'follow' becomes 'segue'.
'this middle' means to look at the middle letters.
'course' becomes 'olden' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The middle letter of 'segue' is 'g'.
'g'+'olden'='GOLDEN'
'to' is the link.
Can you help me to learn more?
(Other definitions for golden that I've seen before include "Valuable" , "Colour of the fleece sought by Jason" , "In Woodstock we are this" , "Type of apple" , "Excellent" .)