1.  A power or privilege held by the general public as the result of a constitution, statute, regulation, judicial precedent, or other type of law.

2.  A legally enforceable claim held by someone as the result of specific events or transactions.  For instance, someone who enters a contract has the right to expect performance from the other party or proper compensation for non-performance.

3.  Loosely, any situation or decision that seems proper or correct by virtue of legal, moral, or ethical ideals (i.e., the opposite of "wrong").  This kind of "right" may not be legally enforceable.  For instance, there may never be a constitution, statute, or judicial precedent that forces people to respect their elders even though many people agree that respecting one's elders is the right thing to do.