Lover, on leaving a country in fact, missing every second (7)
I believe the answer is:
fanatic
'lover' is the definition.
'leaving a country in fact missing every second' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is found in the answer.
'second' could be 'tic' (tic or tick can mean a short amount of time) and 'tic' is present in the answer.
The remaining letters 'fa' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'on' acts as a link.
Can you help me to learn more?
(Other definitions for fanatic that I've seen before include "Obsessive enthusiast" , "enthusiastic" , "Narrow-minded enthusiast" , "Zealot or extremist" , "Devotee beyond reason" .)