noun (1)
\ ˈau̇n(t)s How to pronounce ounce (audio) \

Definition of ounce

 (Entry 1 of 2)

1a : a unit of weight equal to ¹/₁₂ troy pound — see Weights and Measures Table
b : a unit of weight equal to ¹/₁₆ avoirdupois pound
c : a small amount an ounce of sense


noun (2)

Definition of ounce (Entry 2 of 2)

First Known Use of ounce

Noun (1)

14th century, in the meaning defined at sense 1a

Noun (2)

1774, in the meaning defined above

History and Etymology for ounce

Noun (1)

Middle English, from Anglo-French unce, from Latin uncia 12th part, ounce, from unus one — more at one

Noun (2)

Middle English unce lynx, from Middle French, alteration (by misdivision, as if l'once the ounce) of lonce, probably from Old Italian lonza, from Middle Greek lynk-, lynx, from Greek

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Time Traveler for ounce

Time Traveler

The first known use of ounce was in the 14th century

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Cite this Entry

“Ounce.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ounce. Accessed 19 Jun. 2021.

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More Definitions for ounce


\ ˈau̇ns How to pronounce ounce (audio) \

Kids Definition of ounce

1 : a unit of weight equal to ¹/₁₆ pound (about 28 grams)
2 : a unit of liquid capacity equal to ¹/₁₆ pint (about 30 milliliters)


\ ˈau̇n(t)s How to pronounce ounce (audio) \

Medical Definition of ounce

1a : a unit of troy weight equal to ¹/₁₂ troy pound or 31.103 grams
b : a unit of avoirdupois weight equal to ¹/₁₆ avoirdupois pound or 28.350 grams


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