nanosecond

[nan-uh-sek-uh nd, ney-nuh-] /ˈnæn əˌsɛk ənd, ˈneɪ nə-/
noun
1.
one billionth of a second.
Abbreviation: ns, nsec.
Origin
1955-60; nano- + second2
British Dictionary definitions for nanoseconds

nanosecond

/ˈnænəʊˌsɛkənd/
noun
1.
one thousand-millionth of a second ns
Word Origin and History for nanoseconds

nanosecond

n.

1959, from nano- + second (n.).

nanoseconds in Science
nanosecond
  (nān'ə-sěk'ənd)   
One billionth (10-9) of a second.
nanoseconds in Culture
nanosecond [(nan-uh-sek-uhnd)]

A billionth of a second.

Note: The term is often used to refer to a very short time: “He missed having an accident by nanoseconds.”