European comfortable with support in which lives are connected (9)
I believe the answer is:
ecosystem
'in which lives are connected' is the definition.
'european comfortable with support' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'comfortable' becomes 'cosy' ('cosy' can be similar in meaning to 'comfortable').
'with' means one lot of letters go next to another.
'support' becomes 'stem' (I've seen this before**).
'e'+'cosy'+'stem'='ECOSYSTEM'
(Other definitions for ecosystem that I've seen before include "integrated community" , "The interaction of a group of organisms with their physical environment" , "Community of organisms and their environment" , "Biological community with its environment" , "orderly collection of organisms" .)