Mike's dumped by Faith for a girl from Aberdeen? (4)
I believe the answer is:
isla
'a girl from aberdeen?' is the definition.
(common Scottish name)
'mike's dumped by faith' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'dumped by' is a deletion indicator.
'faith' becomes 'islam' (Islam is an example).
'islam' with 'm' taken out is 'ISLA'.
'for' is the link.
(Other definitions for isla that I've seen before include "Lisa (anag.), another girl's name" , "Girl" , "Woman" , "lady from Scotland" , "Scottish lady" .)