effortful
Herculean
abstruse
arduous
backbreaking
brutal
burdensome
complex
critical
crushing
delicate
demanding
difficile
difficult
draining
enervating
exacting
exhausting
fatiguesome
fatiguing
forced
formidable
grueling
hairy
hard
hard-earned
hard-fought
heavy
hefty
intricate
jawbreaking
killing
knotted
knotty
labored
laborious
mean
no picnic
not easy
onerous
operose
oppressive
painful
punishing
rigorous
rough
rugged
set with thorns
severe
circuitous
cross-country
eventful
fruitless
frustrate
hours
irksome
monotonous
perilous
precarious
protracted
thankless
time-consuming
tortuous
uncongenial
uneventful
unprofitable
vexatious
wearisome