heritor
noun
her·i·tor ˈher-ə-tər 
: one that inherits : inheritor
Word History
Etymology
Middle English heriter, heritour, borrowed from Anglo-French heriter, heritier, going back to Vulgar Latin *hērēditārius, noun derivative of Latin hērēditārius "of inheritance, passed by means of inheritance" (Late Latin, "inheriting") — more at hereditary
First Known Use
15th century, in the meaning defined above