Why do so many bad guys and sinister places have names using the syllable “mor”? James Harbeck mentionsMoriarty, Voldemort, Mordor, and Piers Morgan, though he ultimately dismisses the last.
The answer that immediately occurs is etymological: mor- is linked to death in Romance languages, the Germanic mora means darkness, and murder comes from the old English morth.
But Harbeck thinks there’s more than etymology here: “‘mor’ may be what is sometimes called a phonestheme: a part of a word that tends to carry a certain connotation not because of etymology or formal definition but just by association. Words that start with ‘gl’ often have to do with light (glow, gleam, glimmer, glitter, glisten, etc.) even though they are not all related historically; similarly, words that start with ‘sn’ often relate to the nose (snoot, sniffle, snot, snore, sneeze, etc.). It doesn’t mean that all words with those letters have the meaning in common, but there is a common thread among a notable set of them.”
Words sometimes change to take on a phonesthemic quality. “Mordred” was initially Medraut or Modred, equivalent to Moderatus. It changed to Mordred because of Morgan le Fay, but “possibly also through some sound associations, with murder (earlier murther) and with the French morte. After all, the best-known account of the Arthurian legend is Malory’s Le Morte d’Arthur.”
It may be that etymology is more deeply intertwined with meaning than post-Saussurean linguistics supposes.