Six Letter Boy Names

Cathan is one Irish boys' name that remains underused and would be an intriguing way to honor an ancestral Catherine. It is related to Cain and, theoretically, the nouveau Cayden.

Maori form of Thomas

Oengus is the old Irish form of the name most commonly found in the modern world as Angus, typically Scottish.
In Irish mythology, Oengus is the god of youth, love, and poetry.

Think of this as the Hebrew equivalent of Benedict or Benito; best for observant Jews.

Derived from the Choctaw elements tok, meaning "has" and abi, "killer."

Slightly more modern than Walter, but only just.

Nice Scottish sound, but too tied to sweaters and socks.

A common pet name, usually inspired by the Los Angeles Dodgers baseball team, Dodger is used as a given name for around 6 boys every year.

After being one of the hot upscale surnames of the nineties, Garrett has left the Top 100 and this streamlined spelling is dawdling near the bottom of the Top 1000.

Abijah is a truly unusual, truly unisex, truly appealing biblical name. There were several male Abijahs in the Bible, one of them, known as Abijah of Judah, was the fourth king of the House of David, and also a couple of females.

More obscure Irish surname-name, also spelled Molloy, that's prime for use.

A century ago, a handful of boys were named Vivien or Vivian every year compared with thousands of girls. That number has now dwindled to zero.

Subaru is a Japanese astronomical name used for the Pleiades star cluster. The constellation was named as such for Subaru's meaning, "to bunch together," since the stars are crowded together. Subaru is used as a given name for boys in Japan.

If you fit this definition, this might be a clever choice, especially as a middle name.