Left with a new bird seeing light (7)
I believe the answer is:
lantern
'light' is the definition.
(lantern is a kind of light)
'left with a new bird' is the wordplay.
'left' becomes 'l' (common abbreviation).
'with' means one lot of letters go next to another.
'a new' becomes 'an' (I've seen this in other clues).
'bird' becomes 'tern' (tern is a kind of bird**).
'l'+'an'+'tern'='LANTERN'
'seeing' is the link.
(Other definitions for lantern that I've seen before include "Light-admitting structure on roof" , "Light in a transparent protective case" , "Lamp with protective transparent casing" , "Leading light" , "Top of lighthouse" .)