Chemist and singer residing in the outskirts of Darwin (6)
I believe the answer is:
dalton
'chemist' is the definition.
(Dalton is an example)
'singer residing in the outskirts of darwin' is the wordplay.
'singer' becomes 'alto' (alto is a kind of singer).
'residing in' indicates putting letters inside.
'the outskirts of' means to remove the middle letters.
'darwin' with its centre removed is 'dn'.
'alto' put within 'dn' is 'DALTON'.
'and' acts as a link.
(Other definitions for dalton that I've seen before include "John -, chemist who proposed theory of atoms" , "[LAWMAKER] ?" , "John --, English chemist and physicist" , "English scientist" .)