Definitions for "DMZ"
Demilitarized zone. Used by a company that wants to host its own Internet services without sacrificing unauthorized access to its private network. The DMZ sits between the Internet and an internal network's line of defense, usually some combination of firewalls and bastion hosts. Typically, the DMZ contains devices accessible to Internet traffic, such as Web (HTTP ) servers, FTP servers, SMTP (e-mail) servers and DNS servers.
Demilitarised Zone A part of the network that is neither part of the internal network nor directly part of the Internet. Basically a network sitting between two networks.
A DMZ, or DeMilitarized Zone, is a segment of your network specifically for publicly-accessible servers. If you are most familiar with residential-class routers like Linksys and similar, these devices generally incorrectly refer to inbound NAT (opening ports from the internet to your LAN) as "DMZ" functionality. A true DMZ resides on a separate broadcast domain from the LAN, typically on a separate switch using a third interface on the firewall. VLAN's can also be used, but to eliminate the potential of a switch misconfiguration exposing your LAN to your DMZ and the potential effects of VLAN hopping attacks, this is not recommended. The main purpose of a DMZ is to segregate Internet-accessible servers from the LAN, to protect your trusted networks if a DMZ host is compromised. Typical DMZ Configuration.  The following diagram illustrates a typical DMZ configuration.
DMZ is a comic book series published by DC Comics under their Vertigo imprint.