The spelling of the word "Armil" can be a bit confusing. The correct pronunciation is /ˈɑːmɪl/, with the stress on the first syllable. The word refers to a piece of armor that covers the upper part of the arm. The spelling of the word can be explained by the Old French origin of the word, which spelled it as "arme," meaning weapon. Over time, the spelling and pronunciation evolved to "armil." Despite its uncommon usage, it is important to spell the word correctly to avoid confusion.
A kind of sun-dial.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.