Robin's green city (7)
I believe the answer is:
This might be a double definition.
'robin's green' is the first definition.
'lincoln' can be an answer for 'green' (Lincoln green is a shade of green). I'm not sure about the 'robin's' bit.
'city' is the second definition.
(Lincoln is an English city)
Can you help me to learn more?
(Other definitions for lincoln that I've seen before include "US politician?" , "An assassinated US president" , "Capital city of Nebraska" , "US president who gave Gettysburg Address" , "US car marque" .)