American Heritage Dictionary
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Century Dictionary
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GNU Webster's 1913
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WordNet
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Elsewhere on the web
The units commonly used for this measurement are the millimicron which is denoted by the symbol uu, which equals one millioneth of a millimeter; and the Angstrom Unit (A.U.), which is one-tenth millioneth of a millimeter.

Century Dictionary (1)
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Recent Pronunciationsthese grunts every eight hours · haul it off to our darkest dungeon · send for a doctor · forget what witticism you were originally going to insert here because you've just banged your knee on your desk · the rest will come naturally |