In the English alphabet, it's the only polysyllabic letter
In terms of the traditional Welsh alphabet, the name is only 51 
letters long, as certain digraphs ... Schmaltzed and strengthed (10 letters) appear 
to be the longest monosyllabic words recorded in The Oxford English Dictionary, 
while... [DOC] [TLE] 10 Reasons Behind The Quirks Of The English Alphabet - Listverse [PAR] Oct 6, 2014 ... With that kind of a history, it's no surprise that our modern English alphabet is ... 
W is the only letter in the alphabet with a polysyllabic name.