billion
/ˈbɪljən/cardinal number
(pl. billions, 与数词连用时复同单)
1- the number equivalent to the product of a thousand and a million; 1,000,000,000 or 109十亿：
a world population of nearly 5 billion
将近50亿的世界人口
half a billion dollars.
五亿美元。
1.1
billions
informal a very large number or amount of something〈非正式〉大量的, 无数的, 亿万个：our immune systems are killing billions of germs right now.
我们的免疫系统此刻正在杀灭亿万个细菌。
1.2
- a billion pounds or dollars十亿英镑（或美元）：
the problem persists despite the billions spent on it
尽管花了数十亿英镑, 问题依然存在。
1.3
- dated, chiefly Brit. a million million (1,000,000,000,000 or 1012 )〈旧, 主英〉一万亿。
派生词
billionth
ordinal number词源
late 17th cent.: from French, from million, by substitution of the prefix bi- 'two' for the initial letters.