howl at the moon
pound sand
bang one's head against a brick wall
nail Jell-O to a tree
plow the sands
Sisyphean
piss up a rope
bring owls to Athens
futility
mission impossible
struggle
sloggingly
prowl
mug's game
run to waste
pull teeth
exercise in futility
break one's neck
faff
futilely
dead donkey
impairment
Herculean
get blood out of a stone
piss in the wind
polish a turd
constipation
hard yards
stultification
boil the ocean
deadening
make bricks without straw
fool's errand
fight a losing battle
drudgery-ridden
overstrive
shit the bed
difficult
burnt out
fart-arse
laborious
hard going
procrastinatingly
old college try
grail
snorter
despair
bite on granite
do-or-die
stultify
taxing
blow up in one's face
blow up
kamikaze
lamely
tasky
ficklety
pea patch
overtedious
nugatory
putter about
bang away
push string uphill
trouble
waste of time
eke out
waste of effort
moodle
ambitious
tenuity
waste of energy
difficulty
insurmountably
make hard work of
fall flat on one's face
go to pains
boondoggle
thriftless
time-consuming
make a meal of
coquet
laboring oar
move mountains
butchery
grobble
baffle
squirrel cage
rule out
rough sledding
piffle
failable
putter around
like painting the Forth Bridge
hard time
dawdle
prat about
chase a rainbow
kick at an open door