Sportsperson — one you want to get a boundary? (6)
I believe the answer is:
fencer
I believe this is a double definition.
'sportsperson' is the first definition.
(I know that fencer is a type of sportsperson)
'one you want to get a boundary?' is the second definition.
(someone creating fences or boundaries)
(Other definitions for fencer that I've seen before include "who may intervene to keep neighbours apart?" , "He sports with swords" , "Maker of barriers; user of foil" , "armed fighter" , "One using a foil, perhaps" .)