eudemic
long-span
until the cows come home
until the cows freeze over
long
lifetime
eon
hot minute
imperishable
abiding
enduring
longwhiles
aeon
inveterately
at length
forever and a day
eternity
long-pending
with ages
Rome wasn't burned in a day
longue durée
protracted
take time
years
age
long time
drawn-out
prolongably
coon's age
light year
crow's age
indefinitely
yoinks
in the long run
Rome wasn't built in a day
perdurable
undestroyable
indestructible
forever
durable
dog's age
in the long term
blue moon
durative
long haul
make old bones
rot
long-lasting
for the long haul
ages