billionth

adj.第十亿的；十亿分之一的

n.第十亿；十亿分之一

One NM is one-1 billionth meter. 一纳米是十亿分之一米。

Some seismometers are capable of detecting ground motion as small as 1 billionth of a meter,or about 40 billionth of an inch. 一些地震检波器能探测相当于十亿分之一米或亿分之四英寸的地面运动。