Popular half-sister in Bury (5)
I believe the answer is:
inter
'bury' is the definition.
('inter' can be a synonym of 'bury')
'popular half-sister' is the wordplay.
'popular' becomes 'in'.
'half' indicates taking half.
'sister' with half the letters taken is 'ter'.
'in'+'ter'='INTER'
'in' is the link.
(Other definitions for inter that I've seen before include "top Italian side" , "Prefix meaning between or among" , "get put down!" , "Put underground" , "Bury (or, perhaps, Milan)" .)