heir 
(âr)
(âr)n.
1. A person who inherits or is entitled by law or by the terms of a will to inherit the estate of another.
2. A person who succeeds or is in line to succeed to a hereditary rank, title, or office.
3. One who receives or is expected to receive a heritage, as of ideas, from a predecessor.
[Middle English, from Anglo-Norman, from Latin hērēs; see ghē- in the Appendix of Indo-European roots.]