Epithets

An epithet comes from the Greek word epitheton, meaning "attributed or added." It is a byname, or a descriptive term used in place of a name.

Epithets have been applied to real and fictitious people, divinities and objects. There are many epithets for the royals.

Examples have a wide range including Alexander the Great, Richard the Lionheart,  Shakespeare's Romeo and Juliet as "star-cross'd lovers," Superman is the "The Man of Steel", "The Dynamic Duo" is Batman and Robin and New York City is "The Big Apple." 

But not all epithets are so complimentary. Ivan the Terrible may have actually liked having a reputation as being terrible. Racial epithets and ethnic slurs are the ugly side of this language usage.

I'm not sure I completely agree, but one poster says that "If you know a word is either a racial slur or a racial epithet, but can’t decide which, then focus on the primary definition of the word. If the primary definition of the word has to do with racial prejudice, then it’s a racial slur. For example, the “n-word” is a racial slur. By contrast, if the primary definition of the word has little to do with racial prejudice, then it’s a racial epithet. For example, words like ape, brownie, coconut, oreo, crow, eight ball, shine, spade, spook, teapot, and, presumably, cracker, and mayo are racial epithets; not slurs."

Literary epithets are common going back to the classics. Virgil systematically called his main hero "pius Aeneas" (pius meaning religiously observant and humble) but the epithetis not always attached to the character. James Joyce uses the phrase "the snot-green sea" which is a play on Homer's epithet "the wine-dark sea."

Religious epithets are also common. Catholics, Eastern Orthodox Christians, and other Christians use epithets in the veneration of Jesus (e.g., "Christ"; "Prince of Peace"; "The Good Shepherd"), of Mary, Mother of Jesus (e.g. "Mother of God"; "Panagia").

Bluetooth

 Bluetooth Special Interest Group is the standards organisation that oversees  the development of
Bluetooth standards and the licensing of the Bluetooth technologies  and trademarks to manufacturers.

The origin story of the name and logo for the Bluetooth wireless technology standard is an unusual one. This technology that is now commonly used in smartphones, computers and many other devices allows for the exchange of data over short distances.

Bluetooth is managed by the Bluetooth Special Interest Group (SIG) which oversees development of the specification, manages the qualification program, and protects the trademarks.

The name goes back to the 10th century and a Danish King Harald Blatand. King Harald united warring factions in Norway, Sweden, and Denmark under one banner. This was the symbolism in mind when developers of the Bluetooth signal chose the King's name for their technology that could unite many different forms of technology—cars, computers, and mobile phones—under one communications network.

The name Bluetooth is an Anglicised version of the Scandinavian Old Norse Blåtand the epithet of King Harald. The name was proposed in 1997 by Jim Kardach of Intel who had developed a system for mobile phones to communicate with computers, and at that time he was reading the historical novel The Long Ships which is about Vikings and King Harald.

The Bluetooth logo is a ligature of two Runes:
the Runic letter ᚼ (Hagall) and
Runic letter ᛒ (Bjarkan), which are King Harald's initials

TiVo

By TiVo Inc., CC BY-SA 3.0, Link

TiVo (TEE-voh) is a digital video recorder (DVR) developed and marketed by TiVo Corporation and introduced in 1999. TiVo is both the company and the DVR product that allows the scheduled recording of television programs.

As the early leader in this category, the name began to be a generic trademark used for all DVRs, particularly as a verb - "I tivoed that show."

It is sais that hundreds of anmes were considered for the company/product including "Bongo" and "Lasso." The final name is a combination of TV (in caps) for the television aspect, and the i and o (lower case) referencing the acronym "I/O," which is used in tech applications to mean "input/output."