Definition of "one-billionth" []

• One part in a billion equal parts (noun)

WordNet. Princeton University. 2010.

• "The Numbers Guy Blog Radiation Numbers in Damaged Japan Plant Becquerels, grays and sieverts all are internationally accepted units that quantify different aspects of radiation, while micro- and nano- are prefixes denoting one-millionth and one-billionth, respectively."
• "Nowadays the observatory has cesium and hydrogen maser clocks, instruments that deviate no more than one-billionth of a second a day."
• "Google uses perhaps one-billionth of Watson's resources, or less, to handle each query."