The Collaborative International Dictionary of English v.0.48:

Nis \Nis\ [From ne is.]
   Is not. [Obs.] --Chaucer.
   [1913 Webster]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

NIS
       Network Information Service (NSF)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

NIS
       Network Information System (Unix)


The Free On-line Dictionary of Computing (30 December 2018):

Network Information Service
NIS
Yellow Pages

    (NIS) Sun Microsystems' Yellow Pages
   (yp) client-server protocol for distributing system
   configuration data such as user and host names between
   computers on a network.

   Sun licenses the technology to virtually all other Unix
   vendors.

   The name "Yellow Pages" is a registered trademark in the
   United Kingdom of British Telecommunications plc for their
   (paper) commercial telephone directory.  Sun changed the name
   of their system to NIS, though all the commands and functions
   still start with "yp", e.g. ypcat, ypmatch, ypwhich.

   Unix manual pages: yp(3), ypclnt(3), ypcat(1), ypmatch(1).

   (1995-04-08)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

NISI. This word is frequently used in legal proceedings to denote that
something has been done, which is to be valid unless something else Shall be
done within a certain time to defeat it. For example, an order may be made
that if on the day appointed to show cause, none be shown, an injunction
will be dissolved of course, on motion, and production of an affidavit of
service of the order. This is called an order nisi. Ch. Pr. 547. Under the
compulsory arbitration law of Pennsylvania, on the filing of the award,
judgment nisi is to be entered: which judgment is to be as valid as if it
had been rendered on the verdict of a jury, unless an appeal be entered
within the time required by the law.