Unenumerated rights are legal rights inferred from other legal rights that are officiated in a retrievable form codified by law institutions, such as in written constitutions, but are not themselves expressly coded or "enumerated" among the explicit writ of the law.  Alternative terminology sometimes used are: implied rights, natural rights, background rights, and fundamental rights. 
Unenumerated rights may alternatively refer to a situation when an individual or group of people delegate limited powers to a government. "If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended."
Unenumerated rights will be actual rights insofar as they necessitate the systematization of positively enumerated rights anywhere laws would become logically incoherent, or could not be adhered to or maintained in the exclusion of those unenumerated items as rights. Examples of this include federal systems where constituent member constitutions have to be interpreted in relation to their membership in the federal whole, adjudicative of whether authority is rightfully devolved or more rightly federative.
This term alternatively, is used loosely to mean any perceived rights, often considered peremptory or intuitively fiat (such as rights innate to each individual or inherent to mankind), that are without expression or instance of articulation & without consideration of the necessity to their existence extrapolated from the logical unity of other positive rights.
In Australia 
Implied rights are the political and civil freedoms that necessarily underlie the actual words of the constitution but are not themselves expressly stated directly in the constitution. Since the 1990s the High Court has discovered rights which are said to be implied by the very structure and textual form of the Constitution. Chief amongst these is an implied right to freedom of communication on political matters, which was first recognised in Nationwide News Pty Ltd v Wills. In addition, some protections of civil liberties have been the result of the High Court's zealous attempts to safeguard the independence of, and confidence in, the Federal judiciary. A good example of this can be seen in Kable v Director of Public Prosecutions (NSW), in which the High Court struck down a criminal law passed by the New South Parliament that was directed at a single named individual in a similar manner to a Bill of attainder. The High Court also implied a limited right to vote from the text of the Constitution in Roach v Electoral Commissioner, invalidating legislation that prevented all prisoners from voting.
In Ireland 
Article 40.3 of the Irish constitution refers to and accounts for the recognition of unenumerated rights. The Supreme Court is often the main source of such rights, such as the right to bodily integrity, the right to marry and the right to earn a living, among others.
In the Republic of China 
Article 22 of the Constitution of the Republic of China guarantees unenumerated freedoms and rights of the people that are not detrimental to social order or public welfare, now in effect in Taiwan Area.
In the United States 
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
The Supreme Court of the United States has also interpreted the Fourteenth Amendment to the U.S. Constitution to protect against state infringement of certain unenumerated rights including, among others, the right to send one's children to private school and the right to marital privacy.
See also 
- Implied powers
- Letter and spirit of the law
- Positive law
- Unspoken rule
- Natural rights
- Substantive due process