Something no two people can be
I believe the answer is:
trio
(Other definitions for trio that I've seen before include "Group of three (musicians)" , "Archduke, possibly" , "father, spirit and son" , "Group of Magi?" , "Riot (anag)" .)
I believe the answer is:
trio
(Other definitions for trio that I've seen before include "Group of three (musicians)" , "Archduke, possibly" , "father, spirit and son" , "Group of Magi?" , "Riot (anag)" .)