heavy
Herculean
annoying
arduous
arduously
backbreaking
besetting
bothersome
burdensome
burdensomely
crushing
cumbersome
cumbrous
demanding
difficult
difficultly
effortful
encumbering
exacting
exhausting
exigent
forced
grievous
grinding
grueling
hampering
hard
hard-earned
hard-fought
hardly
harsh
heavy-handed
hefty
impedimental
impeding
impeditive
incumbent
irksome
killing
labored
laborious
laboriously
lumpish
massive
onerously
operose
oppressive
overburdensome
exonerate
exoneration
onus
daunt
humiliate
inconvenient
injurious
risky
stressful
stringent
thankless
ticklish
time-consuming
toilsome
troublesome
unenviable
unfavourable
unpopular
vexatious
wearisome
gratuitous