Lewis & Short

† uncĭa, ae, f., = οὐγκία (Siculian and Etruscan; v. Müller, Etrusk. 1, p. 309 sq.) [akin to unus, unicus, unio; Gr. οἰνός], the twelfth part of any thing, a twelfth.

  1. I. Lit.
      1. 1. Of inheritances: mortuus Babullius. Caesar, opinor, ex unciā, etsi nihil adhuc: sed Lepta ex triente, Cic. Att. 13, 48, 1: heres, Sen. Contr. 4, 28 med.; Cod. Just. 5, 27, 2.
        Of a debt: non erit uncia tota, Mart. 9, 3, 5.
      2. 2. To denote a rate of interest, one twelfth per cent. a month, i. e. reckoning by the year, one per cent., Dig. 26, 7, 47, § 4.
      3. 3. As a weight, the twelfth part of a pound (as or libra), an ounce, Rhemn. Fan. Pond. 28; Plaut. Men. 3, 3, 3: uncia aloës, Plin. 20, 13, 51, § 140: Falerni, Mart. 1, 107, 3.
      4. 4. As a measure of land, one twelfth of a jugerum, Col. 5, 1, 10.
      5. 5. As a measure of length, the twelfth part of a foot, an inch, Front. Aquaed. 24; Plin. 6, 34, 39, § 214.
  2. II. Transf., a trifle, bit, atom: neque piscium ullam unciam hodie Pondo cepi, Plaut. Rud. 4, 2, 8; Juv. 11, 131: nulla de nostro nobis uncia venit apro, Mart. 9, 49, 12.