/kwɒ'drɪlɪən; kwɑd`rɪljən/
pron, det, n(pl unchanged or ~s 复数或不变或作 quadrillions) (after a or one, a number, or an indication of quantity 用于a或one之後或用于数目或表示数量的词语之後)
1 (Brit) number shown by
1 followed by
24 zeros; one million to the power of
4 *1後有24个0的数; 一百万的4次幂.
2 (US) number shown by
1 followed by
15 zeros; one thousand to the power of
5 *1後有15个0的数; 一千的5次幂.

number
[Date: 1600-1700; Origin: quadr- + -illion (as in million)]
the number one followed by 15 zeros
BrE old use the number one followed by 24 zeros