The Collaborative International Dictionary of English v.0.48:

Gateway \Gate"way`\ (g[=a]t"w[=a]`), n.
   A passage through a fence or wall; a gate; also, a frame,
   arch, etc., in which a gate in hung, or a structure at an
   entrance or gate designed for ornament or defense.
   [1913 Webster]

WordNet (r) 3.0 (2006):

gateway
    n 1: an entrance that can be closed by a gate

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "gateway":
   French door, archway, back door, barway, bulkhead,
   carriage entrance, cellar door, cellarway, door, doorjamb,
   doorpost, doorway, front door, gate, gatepost, hatch, hatchway,
   lintel, porch, portal, porte cochere, postern, propylaeum, pylon,
   scuttle, side door, stile, storm door, threshold, tollgate, trap,
   trap door, turnpike, turnstile



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

gateway

   1.  A deprecated term for a device that enables
   data to flow between different networks (forming an
   internet).

   Preferred terms are "protocol converter" (connects networks
   that use different protocols), "router" (connects two
   broadcast networks at layer 3 (network layer).  Another
   example is a mail gateway, which is a layer 7 (application
   layer) gateway.

   2.  An interface between an information source
   and a web server.  Common Gateway Interface
   is a standard for such interfaces.  The information source
   can be any system that can be accessed by a program running on
   the web server.  A typical example is a relational
   database.

   (2000-05-24)


U.S. Gazetteer Places (2000):

Gateway, AK -- U.S. Census Designated Place in Alaska
   Population (2000):    2952
   Housing Units (2000): 1084
   Land area (2000):     16.265055 sq. miles (42.126298 sq. km)
   Water area (2000):    0.511929 sq. miles (1.325889 sq. km)
   Total area (2000):    16.776984 sq. miles (43.452187 sq. km)
   FIPS code:            28200
   Located within:       Alaska (AK), FIPS 02
   Location:             61.576398 N, 149.252506 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Gateway, AK
    Gateway


U.S. Gazetteer Places (2000):

Gateway, AR -- U.S. town in Arkansas
   Population (2000):    116
   Housing Units (2000): 48
   Land area (2000):     0.568889 sq. miles (1.473416 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.568889 sq. miles (1.473416 sq. km)
   FIPS code:            26110
   Located within:       Arkansas (AR), FIPS 05
   Location:             36.486000 N, 93.938253 W
   ZIP Codes (1990):     72733
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Gateway, AR
    Gateway


U.S. Gazetteer Places (2000):

Gateway, FL -- U.S. Census Designated Place in Florida
   Population (2000):    2943
   Housing Units (2000): 1322
   Land area (2000):     8.551085 sq. miles (22.147207 sq. km)
   Water area (2000):    0.152297 sq. miles (0.394448 sq. km)
   Total area (2000):    8.703382 sq. miles (22.541655 sq. km)
   FIPS code:            25655
   Located within:       Florida (FL), FIPS 12
   Location:             26.574686 N, 81.754532 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Gateway, FL
    Gateway