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1. The ordinal number matching the number one billion in a series.
2. One of a billion equal parts.

bil′lionth adj. & adv.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.billionth - position 1,000,000,000 in a countable series of things
U.S.A., United States, United States of America, US, USA, America, the States, U.S. - North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
rank - relative status; "his salary was determined by his rank and seniority"
2.billionth - one part in a billion equal parts
common fraction, simple fraction - the quotient of two integers
Adj.1.billionth - the ordinal number of one billion in counting order
ordinal - being or denoting a numerical order in a series; "ordinal numbers"; "held an ordinal rank of seventh"
واحد من بليون
einn biljónasti; einn òúsund miljónasti
milyarda birtrilyonda bir


adjmilliardste(r, s); (dated Brit) → billionste(r, s)
nMilliardstel nt; (dated Brit) → Billionstel nt


(ˈbiljən) plurals ˈbillion (1 ~3), ˈbillions (2, ~3) – noun
1. often in the United Kingdom, the number 1,000,000,000,000; in the United States, and often in the United Kingdom, the number 1,000,000,000. a billion; several billion.
2. often in the United Kingdom, the figure 1,000,000,000,000; in the United States, and often in the United Kingdom, the figure 1,000,000,000.
3. a billion pounds or dollars. The sum involved amounts to several billion(s).
often in the United Kingdom, 1,000,000,000,000 in number; in the United States and often in the United Kingdom, 1,000,000,000 in number. a few billion stars.
billionaire (ˌbiljəˈneə(r)) noun
a very rich person who has more than a billion dollars, pounds etc. He's not just a millionaire – he's a billionaire!
ˈbillionth noun
one of a billion equal parts.
References in classic literature ?
No," replied Barbicane, "because the terrestrial atmosphere absorbs four-tenths of the solar heat; besides, the quantity of heat intercepted by the earth is but a billionth part of the entire radiation.
The shipment of our 10 billionth PIC microcontroller is a remarkable achievement, and shipping it to a giant in the electronics industry like Samsung makes it even more satisfying," said Microchip's president and CEO Steve Sanghi.
When India reaches its one billionth person, it will have a population density of 788 people per square mile.
A nanometer is a billionth of a meter -- 80,000 times thinner than a human hair.
00, America's number one dollar store with over 400 retail locations nationwide, announced today it shipped its one billionth item for sale at $1.
Physical chemistry today, she relates, enables scientists to discern the composition of stars without leaving Earth and also to understand activity at the scale of a billionth of a meter.
its 1 billionth debit card transaction at merchant locations, a first
Nanoscale sensing and nanofabrication (nanometer = one billionth of a meter) are hot topics, as are fiber sensor networks that can detect chemical or biological contamination across a wide area.
But today, Delta Air Lines reached a major historical milestone, as it boarded its 1 billionth revenue passenger in the airline's 63-year history of passenger service.
NASDAQ:MCHP), a leading provider of microcontroller and analog semiconductors, announced today that it shipped its four billionth PIC(R) microcontroller, the PIC16F877 high-performance Flash microcontroller, to Insta Elektro of Ludenscheid, Germany.
NEW YORK -- The International Securities Exchange (NYSE:ISE) said today that it traded its one billionth contract, an important milestone in the evolution of the first fully-electronic options market in the US.