Attention given to item about large life-form in solar System (9)
I believe the answer is:
earthling
'life-form in solar system' is the definition.
(life-form from Earth)
'attention given to item about large' is the wordplay.
'attention' becomes 'ear' (having someone's ear is having their attention).
'given' means one lot of letters go next to another.
'to item' becomes 'thing' (both can mean an object).
'about' is an insertion indicator.
'large' becomes 'L' (eg in clothes sizes).
'thing' enclosing 'l' is 'thling'.
'ear'+'thling'='EARTHLING'
(Other definitions for earthling that I've seen before include "Human being (sci-fi)" , "Man of the world" , "man so to be called from space?" , "sci-fi character" .)