abysm
abyss
allay
arroyo
bar
barrier
batten
blank wall
blind alley
blind gut
block
blockade
blockage
bolt
bolt down
bottleneck
box canyon
breach
break
canyon
cavetto
cavity
cecum
chap
chasm
check
chimney
chink
choke
choking
choking off
cleft
cleuch
clog
clough
clove
cloy
col
congest
congestion
constipation
costiveness
coulee
couloir
crack
cram
cranny
crevasse
crevice
crowd
bastion
eat
mountain pass
muscle system
muscular structure
musculature
notch
pass
passage
passageway
gorged
gorges
gorgess
gorging
bluff
cavern
cleave
crater
creek
fissure
foothill
glacier
glen
hillside
ledge
peak
plateau
precipice
ravine
ridge
swamp
valley
waterfall
George
Norge
disgorge
forge