tasteless
uninteresting
arid
banal
bare
barren
betwixt and between
blah
bland
blank
bleached
bloodless
boring
bromidic
changeable
characterless
clear
cold
colorless
colourless
common
commonplace
corny
dead
devoid
dilute
diluted
dismal
distasteful
draggy
drearisome
dreary
driveling
dry
dryasdust
dull
dusty
effete
elephantine
empty
etiolated
fade
fair
fair to middling
fairish
fatuous
featureless
feeble
insipient
disagreeable
lifeless
meaningless
monotonous
prosaic
stale
stupid
tame
tiresome
trite
trivial
unmeaning
vapid