Having its own or a single nature or character throughout, as in colour, composition, etc., without addition or change; of the same kind; unmixed.
a self bow: one made from a single piece of wood
2
Same, identical.
3
Belonging to oneself; own.
4
Of or relating to any molecule, cell, or tissue of an organism's own (belonging to the self), as opposed to a foreign (nonself) molecule, cell, or tissue (for example, infective, allogenic, or xenogenic).