简写为十亿分之一的意思
nano-
/nan'oh/ 1. A {prefix} meaning 10^-9 or one billionth.
Used loosely to mean "small", e.g. {nanotechnology}, or
(rarely), following "nanosecond", to mean a short time,
e.g. "I'll be with you in a nano".
[{Jargon File}]
(2002-03-02)