UNCIA

uncia (<<schwa>>n-shee-<<schwa>>), n. [Latin] 1.Roman law. One-twelfth of the as (a pound or, by analogy, an estate or inheritance). • The English word ounce is derived from this term. Cf. AS; BES. 2.Hist. A measure of land used in a royal charter. • The size of an uncia is unclear, but it may have measured 1,200 square feet (i.e., 12 modii).3. Generally, the proportion of one-twelfth.
[Blacks Law 8th]