Following are all the underpassage like words, in the list below.
PASSAGE
100% like underpassage
PASSAGEWAY
100% like underpassage
UNDERWAY
99.99% like underpassage
FOREPASSAGE
99.99% like underpassage
UNDERBRIDGE
99.98% like underpassage
PUSH-THROUGH
99.98% like underpassage
CROSSUNDER
99.98% like underpassage
TUNNELWAY
99.97% like underpassage
CELLARWAY
99.97% like underpassage
BACK PASSAGE
99.96% like underpassage
SUBTERRAIN
99.96% like underpassage
UNDERCHAMBER
99.96% like underpassage
SUBTERRANE
99.95% like underpassage
UNDERCROFT
99.95% like underpassage
UNDERCELLAR
99.94% like underpassage
UNDERHALLS
99.94% like underpassage
BACKWAY
99.94% like underpassage
UNDERSTAIRS
99.93% like underpassage
PASSTHROUGH
99.93% like underpassage
COMMUNICATION
99.92% like underpassage
LADDERWAY
99.92% like underpassage
PASSAGE HOUSE
99.92% like underpassage
CAVERN
99.91% like underpassage
BACK ALLEYWAY
99.91% like underpassage
UNDERNEATHNESS
99.9% like underpassage
ENTERCLOSE
99.9% like underpassage
HYPOGEUM
99.9% like underpassage
GROTTO
99.89% like underpassage
OUTGANG
99.89% like underpassage
CORRIDOR
99.88% like underpassage
OUTLET
99.88% like underpassage
FOOTWAY
99.88% like underpassage
COVERT
99.87% like underpassage
TUNNEL
99.87% like underpassage
INLET
99.86% like underpassage
SCREENS PASSAGE
99.86% like underpassage
ALCOVE
99.86% like underpassage
AREAWAY
99.85% like underpassage
GATE
99.85% like underpassage
PASSAGE-HOUSE
99.84% like underpassage
GANGWAY
99.84% like underpassage
DOORWAY
99.84% like underpassage
ESCAPE ROUTE
99.83% like underpassage
CROSSOVER
99.83% like underpassage
SUBWAY
99.82% like underpassage
WAY OUT
99.82% like underpassage
SLIP
99.82% like underpassage
DOWN
99.81% like underpassage
WAY IN
99.81% like underpassage
BACK DOOR
99.8% like underpassage
HIDEOUT
99.8% like underpassage
SIDE ENTRANCE
99.8% like underpassage
UNDERCITY
99.79% like underpassage
HYPHEN
99.79% like underpassage
DOWNSTAIRS
99.78% like underpassage
EGRESS
99.78% like underpassage
GARBAGE CHUTE
99.78% like underpassage
HALLWAY
99.77% like underpassage
BARRIER
99.77% like underpassage
HYPOGAEUM
99.76% like underpassage
BACKSTAIRS
99.76% like underpassage
SOUTERRAIN
99.76% like underpassage
HIDING PLACE
99.75% like underpassage
HALL
99.75% like underpassage
INCLINE
99.74% like underpassage
PASSE-PARTOUT
99.74% like underpassage
BACKSTAIR
99.74% like underpassage
ROOM
99.73% like underpassage
AVEN
99.73% like underpassage
GETAWAY
99.72% like underpassage
OPEWAY
99.72% like underpassage
UNDERKEEP
99.72% like underpassage
HATCH
99.71% like underpassage
CRAWL SPACE
99.71% like underpassage
RATHOLE
99.7% like underpassage
BARWAY
99.7% like underpassage
SUBROOM
99.7% like underpassage
FOOTBRIDGE
99.69% like underpassage
DUNGEON
99.69% like underpassage
ACCESSWAY
99.68% like underpassage
ENTRY
99.68% like underpassage
CROFT
99.68% like underpassage
BASEMENT
99.67% like underpassage
EMERGENCY ESCAPE
99.67% like underpassage
OUTGATE
99.66% like underpassage
AVENUE
99.66% like underpassage
CATACOMB
99.66% like underpassage
OUBLIETTE
99.65% like underpassage
ALLEYWAY
99.65% like underpassage
EXIT
99.64% like underpassage
BACK STREET
99.64% like underpassage
RECESS
99.64% like underpassage
ENTRYWAY
99.63% like underpassage
TRAP
99.63% like underpassage
BACK ALLEY
99.62% like underpassage
INGRESS
99.62% like underpassage
STAIRCASE
99.62% like underpassage
ANTECHAMBER
99.61% like underpassage
CROSSROAD
99.61% like underpassage
FLOORWAY
99.6% like underpassage