Editor on Telegraph supporting university is capable of learning (8)
I believe the answer is:
educable
'capable of learning' is the definition.
(I've seen this in another clue)
'editor on telegraph supporting university' is the wordplay.
'editor' becomes 'ed' (abbreviation).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'telegraph' becomes 'cable' (synonyms).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'university' becomes 'U' (abbreviation for university).
'cable' put after 'u' is 'ucable'.
'ed'+'ucable' is 'EDUCABLE'.
'is' is the link.
(Other definitions for educable that I've seen before include "Capable of being taught" , "as good students should be" , "can take in information" , "Able to be trained" .)