gateway

noun

1. A passage that can be closed by use of a gate.

   “The original family who had begun to build a palace to rival Nonesuch had died out before they had put up little more than the gateway, […].”

2. A place regarded as giving access to somewhere.

   “The staff offer a touch of Norfolk courtesy as they guide passengers onto connecting services. The bustling concourse has a wide selection of information and retail, including a very active city tourism presence. This station now feels like a real gateway to Norwich.”

3. Any point that represents the beginning of a transition from one place or phase to another.
4. (attributive)Any point that represents the beginning of a transition from one place or phase to another.

   “a gateway drug”

   “Just as they say that marijuana leads to harder drugs, Gallegly is claiming that crush is a “gateway fetish”—a term I've never heard before. He claims that if someone starts with bugs they'll end up escalating to human babies in no time.”

   “According to Mellody, love addiction is a gateway addiction leading to additional addictions: to sex, food, drugs, alcohol, and so on.”

5. A point at which freight moving from one territory to another is interchanged between transportation lines.
6. In wireless internet, an access point with additional software capabilities such as providing NAT and DHCP, which may also provide VPN support, roaming, firewalls, various levels of security, etc.

verb

1. (transitive)To make available using a gateway, or access point.