climbable
navigable
negotiable
satisfactory
surmountable
travelable
traversable
OK
acceptable
accessible
adequate
admissable
admissible
agreeable
all right
allowable
alright
attainable
average
better than nothing
betwixt and between
current
decent
dull
fair
fair to middling
fairish
good enough
goodish
indifferent
insipid
lackluster
mediocre
medium
middling
moderate
modest
namby-pamby
not amiss
not bad
not half bad
not so bad
of a kind
of a sort
of sorts
okay
open
presentable
pretty good
reachable
respectable
breathable
credible
creditable
discernable
discernible
distinguishable
drinkable
endurable
intelligible
legible
penetrable
perceptible
practicable
procurable
recognisable
so-so
tenable
tolerable
impassable