|Origin:||Perhaps from nock 'small cut in the end of a bow for the string to fit in' (14-20 centuries)|
just before it is too late, or just before something bad happens:
Luckily, help arrived in the nick of time.
2 British English informal
in good condition or in bad condition:
It's an old car but it's still in good nick.
a very small cut made on the edge or surface of something
4 British English informalSCJ
a police station