Namesake is a term used to characterize a person, place, thing, quality, action, state, or idea that has the same, or a similar, name to another - especially (but not exclusively) if the person or thing is actually named after, rather than merely sharing the name of another.
For example, if a person, place, or thing has the same name as another - especially if they are named after another person, place, or thing, then the name target is said to be the namesake of the name source. The earliest use reported in the Oxford English Dictionary was in 1635. Dictionaries suggest that the word probably comes from "name's sake", "for one's name('s) sake", for "name sake".
The term namesake was first recorded in 1635, referring to a place with the same name as another. Among other recordings, a 1646 usage was carried through in an 1806 publication, entitled A Critical Pronouncing Dictionary, and Expositor of the English Language. Modern-day usage has expanded to several uses for the term.
Naming a child after a relative, friend, or well-known person is a fairly common practice. In the case of sons named for their father this can necessitate "Jr.", "III", and other name suffixes in order to distinguish - especially when both father and son become famous. Use of a namesake's name in a leadership position may indicate certain things, usually referring to certain traits of the namesake, such as in the use of papal regnal names.
Some commercial entities and products are named after their creators, such as the Trump Tower and Ford Motor Company. Items are also named after people associated with them, such as the teddy bear. This is especially the case with scientific discoveries and theories, such as Gibbs free energy. When the target name merely is derived from the source name without an additional "sake" connection, such usage more accurately may be called an eponym rather than a namesake.[clarification needed]
Discrepancies in meaning (US usage)
There has been some discrepancy as to whether the name source or the name target takes the term namesake. According to the American Heritage Dictionary, a namesake is a person or thing named after another. In other words, the name target takes the term namesake, as in
"I was named after my grandfather. I am his namesake."
Casual or accidental identification of personal namesakes can occur in daily life via a number of sources, including: telephone directories, newspaper births/deaths/marriages announcements, dictionaries of biography, internet search engines, etc.
There are some notable examples of deliberate searching for and identification of non-related personal namesakes.
Starting with a drunken wager, British Comedian Dave Gorman used a wide variety of methods to find namesakes, an exercise which then evolved into a 2001 stage show "Are You Dave Gorman" and which was subsequently made into a book and television series .
US actor/filmmaker Jim Killeen used the Google search engine to find personal namesakes for his 2007 documentary "Google Me" [dead link]
Look up namesake in Wiktionary, the free dictionary.
Code name, word or name used clandestinely to refer to another name or word