Security Glossary - N

This glossary has been created to assist security professionals in defining security terms commonly used by the profession and the industry, worldwide. It is a developing list that will be maintained, and where appropriate, modified, and changed over time. Terms borrowed from related fields, such as engineering, investigations, safety, etc. will be included when deemed necessary for the security professional.


The definition's source is cited in brackets [ ] following the definition. View the key to all cited reference sources.

It is NOT our goal to publish this glossary in print since it is intended to be a current online reference (on the ASIS website) to serve the security professional on an ongoing basis.

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natural disaster

​a naturally occurring calamitous event bringing great damage, loss, or destruction such as tornadoes, hurricanes, earthquakes, and related occurrences.
[ASIS GDL GLCO 01 012003]

negligent hiring

​the failure to use reasonable care in the employee selection process, resulting in harm caused to others. Employers have a legal duty not to hire people who could pose a threat of harm to others, which can include everything from slight to fatal bodily injury, theft, arson, or property damage. The definition of ‘‘reasonable care’’ depends on the degree of the risk of harm to others. The greater the risk, the higher the standard of care required.

net centric

​A continuously-evolving and complex community of people, devices, information, and services interconnected by a communications network to optimize resource management and provide superior information on events and conditions needed to empower decision makers.
[ANSI/ASIS SPC.4-2012]

nolo contendere

​the name of a plea in a criminal action, having the same legal effect as a plea of guilty, so far as regards all proceedings on the indictment, and on which the defendant may be sentenced. (Latin for “I will not contest it”)


​non-fulfillment of a requirement.     
[ASIS SPC.1-2009]  [ANSI/ASIS PAP.1-2012]  ​[ANSI/ASIS PSC.1-2012]  [ANSI/ASIS PSC.2-2012]


​Failure to fulfill a requirement.

non-disclosure agreement (NDA)

​a legal contract between at least two parties that outlines confidential materials or knowledge the parties wish to share with one another for certain purposes, but wish to restrict from generalized use. In other words, it is a contract through which the parties agree not to disclose information covered by the agreement. 
[ASIS GDL IAP 05 2007]

non-lethal weapons

​Weapons, devices, and munitions that are explicitly designed and primarily employed to immediately incapacitate targeted personnel or materiel, while minimizing fatalities, permanent injury to personnel, and undesired damage to property in the target area or environment. Non-lethal weapons are intended to have reversible effects on personnel and material.
[ANSI/ASIS PSC.4-2013]


​recognized and accepted rules of social behavior.
[ANSI/ASIS PSC.1-2012]