Relation to treat with consideration (7)
I believe the answer is:
respect
I believe this clue is a double definition.
'relation' is the first definition.
(I've seen this before)
'treat with consideration' is the second definition.
(I've seen this before)
'to' is the link.
(Other definitions for respect that I've seen before include "Show deference (to)" , "Look up to" , "Feeling of deep admiration" , "Due regard; admiration" , "Hold in high regard" .)