Initially ring up relatives after leaving country (5)
I believe the answer is:
rural
'country' is the definition.
(I know that country can be written as rural)
'initially ring up relatives after leaving' is the wordplay.
'initially' indicates taking the first letters.
The initial letters of 'ring up relatives after leaving' is 'RURAL'.
(Other definitions for rural that I've seen before include "outside the city?" , "Connected with farming" , "Characteristic of the countryside" , "Characteristic of country life" , "Old country fellow" .)