Etymology: In Old English < an unattested post-classical Latin variant (showing -ts- for -c- before i ) of classical Latin uncia (see below). In Middle English largely reborrowed < (i) Anglo-Norman and Middle French unce (also in Anglo-Norman as ounce , ounse , and in Middle French as once ; French once ) unit of weight (early 12th cent. in Anglo-Norman in the phrase ne unce de not a bit of; 2nd half of the 12th cent. in Old French as once ), gold coin (c1135 in Old French in the phrase once d'or ), in Anglo-Norman also in sense ‘inch’, and their etymon (ii) classical Latin uncia twelfth part, a unit of weight equal to one-twelfth of a pound, a measure of length equal to one-twelfth of a foot, a measure of land area equal to one-twelfth of a iugerum (see juger n.), in post-classical Latin also a measure of time equal to 47 atoms (c1230–50 in Bartholomaeus Anglicus: compare quots. a1398 at sense 3), a measure of length equal to three inches (c1230–50 in Bartholomaeus Anglicus: compare quot. a1398 at sense 4), a monetary unit, a gold coin (mid 11th cent. with reference to Spain, early 14th cent. with reference to Sicily; often as uncia auri ounce of gold), ultimately < ūnus one adj. Compare Old Frisian enze (which on formal grounds could be taken as cognate with Old English, indicating early borrowing), Old High German unza (Middle High German unze , German Unze ), Early Irish ungae , Portuguese onça unit of weight, coin (1114 as †unza ), Spanish †onça (first half of the 13th cent.), onza (1250) unit of weight, gold coin, Italian oncia gold coin (1231–50 as †onza ), very small amount (a1313), unit of weight (a1321), Catalan unça , †onça unit of weight, coin (13th cent.), Old Occitan onsa (a1240; Occitan onça ) unit of weight, one-eighth of a minute. Compare inch n.¹, a parallel borrowing from classical Latin uncia.The β. forms show metanalysis (see N n.).

Etymology: < Middle French once lynx (1284 in Old French; c1179 denoting the first beast of the Apocalypse), panther (1576; French once ), variant (probably arising by misapprehension of the first syllable as showing the definite article le ) of Old French lonce (although this is only attested later: late 13th cent. in the Voyages de Marc Pol) < Italian lonza panther (13th cent.), ultimately < ancient Greek λύγξ lynx n. Compare ( < Italian) Catalan onça (13th cent.; also as †unça), Spanish onza (1250 as †onça), Portuguese onca (1516). In Middle English form vnce probably after post-classical Latin uncea (13th cent. in British sources).Italian lonza was perhaps borrowed directly from Greek λύγξ in the period of the first crusades; the Greek word was pronounced with /u/ by the merchants of Asia Minor who traded in fur and wild animals (see Giornale Storico 53 (1909) 17-18).

Etymology: < ounce n.¹ In sense 1 after post-classical Latin unciare (in an undated glossary in Du Cange, and compare the Latin form in quot. a1425 at sense 1); compare also Middle French oncier (1487 or earlier). N.E.D. (1903) gives the pronunciation as (ɑuns) /aʊns/.