tunnel (n.)
- access
- adit
- aisle
- alley
- ambulatory
- aperture
- arcade
- artery
- avenue
- bore
- bunker
- burrow
- cave
- cavern
- channel
- cloister
- colonnade
- communication
- conduit
- connection
- corridor
- couch
- countermine
- countersink
- course
- cove
- covert
- defile
- den
- dig
- dike
- ditch
- dive
- dredge
- drill
- drive
- duct
- dugout
- earth
- egress
- entrance
- entrenchment
- exit
- ferry
- ford
- form
- fosse
- foxhole
- furrow
- gallery
- gouge
- groove
- grot
- grotto
- grub
- hole
- ingress
- inlet
- interchange
- intersection
- junction
- lair
- lane
- lodge
- lower
- mew
- mine
- moat
- opening
- outlet
- overpass
- parallel
- pass
- passage
- passageway
- portico
- quarry
- run
- sap
- scoop
- scrabble
- scrape
- scratch
- sewer
- shaft
- shovel
- sink
- spade
- subway
- trench
- trough
- underpass
- warren
- way
tunnel (v.)
- access
- bore
- bunker
- burrow
- cave
- cavern
- channel
- cloister
- couch
- countermine
- countersink
- course
- deepen
- defile
- delve
- den
- depress
- dig
- dike
- ditch
- dive
- dredge
- drill
- drive
- duct
- earth
- egress
- entrance
- excavate
- exit
- ferry
- ford
- form
- furrow
- gouge
- groove
- grub
- hole
- interchange
- lane
- lodge
- lower
- mew
- mine
- parallel
- pass
- penetrate
- quarry
- run
- sap
- scoop
- scrabble
- scrape
- scratch
- shaft
- shovel
- sink
- spade
- trench
- way
