What is nscd?

["Peter Kim" <peter@twinsun.co.jp>]

I'm currently setting up several linux machines.

When I leave my machines for awhile - a few hours - the terminal screen
fills with the message:

nscd: 222: while accepting conection: Cannot allocate memory.

My screen is completely filled with this error message.  Each machine
displays a different number in place of 222.

I've figured out that the 222 is a process id.  I've discovered that there's
a /usr/sbin/nscd.

I've tried man nscd and I get the following error:
man: warning: /usr/share/man/man8/sigfetch.8.gz: whatis parse for
sigfetch(8) fariled
No manual entry for nscd

I've tried apropos nscd  and  I get:
there's nothing appropriate

What is nscd and why is it giving me these messages?

Any ideas?

Thanks,
Peter