until the cows freeze over
until the cows come home
at length
inveterately
hot minute
long-span
eon
lifetime
abiding
imperishable
enduring
longwhiles
long
forever and a day
with ages
eudemic
eternity
coon's age
years
crow's age
light year
forever
dog's age
aeon
ages
blue moon
donkey's
age
grip
donkey's ears
donkey's years
long time
overlong
long-pending
for long
no end
indestructible
in the long term
durable
perdurable
in the long run
undestroyable
month of Sundays
take time
protracted
long as one's arm
durative
longish
for the long haul
in perpetuity
superlong
overrun
longtime
momentaneous
long haul
fugitive
momentary
fleeting
time out of mind
prolongedly
drawn-out
longue durée
ultralong
macrobiotic
at last
cycle
lengthen
Rome wasn't burned in a day
overprotracted
yoinks
till doomsday
Rome wasn't built in a day
long-termly
yonks
chronic
period
long ass
stretch
drag on
continuing
lengthily
make old bones
indefinitely
time-consumingly
interval
dragging
permanent
long-lasting