trillionth       
 ordinal number uk/ˈtrɪl.jənθ/ us/ˈtrɪl.jənθ/
 万亿的序数词,第一万亿个
1,000,000,000,000th written as a word
  In July, the company's web engineers said they had registered the trillionth web page available via the search engine. 7月,该公司的网络工程师表示,他们已经通过搜索引擎发现了第 1 万亿个网页。 
informal He doesn't laugh when I miss the ball for the trillionth time (= I've already missed it a lot of times). 尽管我老是接不着球,但他并不耻笑我。 
 See: trillion
 - More examples
 - What will the world look like by the time the trillionth baby arrives?
 - This documentary must be about the trillionth to be screened starring the shark.
 - I gave her my card and apologized for the nine trillionth time.
 
trillionth       
noun [ C ] uk/ˈtrɪl.jənθ/ us/ˈtrɪl.jənθ/
 万亿分之一
one of 1,000,000,000,000 equal parts of something
  The new particles decay after only trillionths of a second. 新粒子仅在万亿分之一秒后就衰变了。 
 The samples are measured in trillionths of a gramme. 样品的测量单位为万亿分之一克。 
 See: trillion
 - More examples
 - The currency was worth less than one trillionth of a US cent.
 - I do not have a device which can actually measure my height to a trillionth of a metre.
 - A bacterium weighs only about a trillionth of a gram.