In the United States Declaration of Independence, the term "unalienable rights" signifies rights that are granted by the Creator and cannot be taken away from the people. The rights listed in the same sentence are the rights to life, liberty and the pursuit of happiness.
UShistory.org explains that in the various drafts of the Declaration of Independence, the words "unalienable" and "inalienable" were both used. These words have the same definition, but "inalienable" is more commonly used in modern English. It is believed that John Adams may have made the final decision to use the word "unalienable" instead of "inalienable" to describe the rights that cannot be taken from the people.