The Collaborative International Dictionary of English v.0.48:
flytrap \fly"trap\ (fl[imac]"tr[a^]p), n.
1. A trap for catching flies.
2. (Bot.) A plant (Dion[ae]a muscipula), called also
Venus's flytrap, having two-lobed leaves which are
fringed with stiff bristles, and fold together when
certain sensitive hairs on their upper surface are
touched, thus trapping insects that light on them. The
insects so caught are afterwards digested by a secretion
from the upper surface of the leaves. The plant is native
to North and South Carolina, growing in bogs.
The Free On-line Dictionary of Computing (30 December 2018):
A dedicated gatewayserver with special
security precautions on it, used to service external connections
(typically from the public Internet). The firewall machine
protects servers and networks hidden behind it from crackers.
The typical firewall is an inexpensive microprocessor-based
Unix machine with no critical data, with public network ports on
it, but just one carefully watched connection back to the rest of
the cluster. The special precautions may include threat
monitoring, call-back, and even a complete iron box keyable to
particular incoming IDs or activity patterns.
The type of network and security environment of a firewall machine
is often called a De-Militarised Zone (DMZ). It may contain
other servers such as e-mail servers or proxy gateways -
machines that need to be publicly accessible but also need some
access to internal systems.
Also known as a (Venus) flytrap after the insect-eating plant.