Tend to swear after nationalist ousts leader (5)
I believe the answer is:
nurse
'tend to' is the definition.
(I've seen this before)
'swear after nationalist ousts leader' is the wordplay.
I cannot really see how this works, but
'nationalist' could be 'n' (abbreviation in politics) and 'n' is located in the answer.
'leader' could be 'e' (I've seen this in other clues) and 'e' is found within the answer.
The remaining letters 'urs' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for nurse that I've seen before include "Tend - care for" , "one working in theatre" , "Nanny" , "Professional carer" , "Sister, e.g." .)