billionth
/ˈbɪljənθ/numeral [序数词] 第十亿个
I have to go after Steve Mercer, she thought for probably the billionth time. 我一定要去找史蒂夫·默瑟，这大概是她第十亿次这样想了。
noun [专属名词] 十亿的（人或物）；十亿分之一
...a billionth of a second. ...十亿分之一秒。
adjective [原级] 第十亿个的
Thus time and time's relativity are measurable by any hourglass, alarm clock, or atomic clock that can measure a billionth of a second. 因此，时间和时间的相对性可以用任何沙漏、闹钟或原子钟来测量，其中原子钟可测量出十亿分之一秒。
adverb [方式副词] 第十亿个地
A nanometre is a billionth of a metre. 十亿分之一米是一纳米。
