A underground passageway, especially one for trains or cars that passes under a mountain, river or a congested urban area.
An Internet Protocol (IP) network communications channel between two networks. It is used to transport another network protocol by encapsulation and often encryption of its packets.
a hole in the ground made by an animal for shelter
move through by or as by digging; "burrow through the forest"
a passage through or under something, usually underground (especially one for trains or cars); "the tunnel reduced congestion at that intersection"
force a way through
a passageway through or under something, usually underground (especially one for trains or cars); "the tunnel reduced congestion at that intersection"
a passageway through or under something, usually underground (especially one for trains or cars)
