The Obscure Origins and Meaning of the Term "Uncial" for Script

"The meaning of the term 'Uncial' is obscure. Jerome is said to have been the first to speak of 'litterae uncialibis', a phrase which has perhaps been too literally translated as 'inch-high letters'. No ancient example of Uncial, used as text, nor any other early book script, comes anywhere near that size. Bischoff (Latin Palaeography, Antiquity and the Middle Ages) believes that Mabillon (a 17th century scholar) mistakenly applied Jerome's 'uncialibus' to this one style of script, and the error has been perpetuated ever since. Leonard Boyle (Medieval Latin Palaeography) suggests that 'uncialibis' is perhaps a mistranslation of 'initialibis'" (Stan Knight, Historical Scripts from Classical Times to the Renaissance [2009] 35).