1640s, "pertaining to an ounce," from Latin uncialis "of an inch, of an ounce," from uncia "a twelfth part" (see inch). In reference to letters, it is attested from 1712, from Late Latin litterae unciales (Jerome), probably meaning "letters an inch high," from Latin uncialis "of an inch, inch-high."
in calligraphy, ancient majuscular book hand characterized by simple, rounded strokes. It apparently originated in the 2nd century AD when the codex form of book developed along with the growing use of parchment and vellum as writing surfaces. Unlike its prototype square roman, uncial is adapted to direct strokes of the pen held in one position and was thus the natural favourite of scribes; most of the works of Latin literature for more than 500 years were copied in this hand