billionth
ordinal number uk/ˈbɪl.jənθ/ us/ˈbɪl.jənθ/
第十亿个
1,000,000,000th written as a word
billionth
noun [ C ] uk/ˈbɪl.jənθ/ us/ˈbɪl.jənθ/
十亿分之一
one of a billion equal parts of something
a/one billionth of a second 十亿分之一秒