Nun's relative (6)
This clue is a double definition.
'nun's' is the first definition.
(Sister is an example)
'relative' is the second definition.
(I know that sister subproperty of relative)
(Other definitions for sister that I've seen before include "woman in hospital" , "Resist about the sibling" , "Nurse, nun and sibling" , "habits' - one who has them" , "Resist (anag) - nurse" .)
(Other definitions for monk that I've seen before include "One vowed" , "prayer?" , "Trappist, for example" , "Religious brother" , "Setter" .)