retentive
water-repellent
water-resistant
close
close-knit
close-textured
close-woven
closed
compact
compacted
compressed
concentrated
concrete
condensed
congested
consolidated
crammed
crammed full
crowded
dense
firm
gluey
hard
heavy
hermetic
holeproof
impassable
impenetrable
impervious
jam-packed
jammed
massive
nonporous
nonpuncturable
packed
punctureproof
sealed
serried
solid
substantial
thick
thick-growing
thickset
unpassable
unperforable
unpierceable
viscid
viscose
viscous
air-tight
alluvial
bituminous
calcareous
clayey
flammable
friable
insulate
neoprene
oil-bearing
opaque
outermost
permeable
porous
resistant
sealed-off
seamless
sedimentary
soundproof
unreadable
valueless
water-tight
waterproof