Relative from Totnes is terse (6)
I believe the answer is:
sister
'relative' is the definition.
(I know that sister has the subproperty of relative)
'from totnes is terse' is the wordplay.
'from' says the answer is hidden in the clue.
'SISTER' is hidden in the letters of 'totnes is terse'.
(Other definitions for sister that I've seen before include "Close female relative" , "trade union member?" , "A kinswoman" , "Nurse, nun or relation" , "Relative in hospital?" .)