historically
uncommonly
rarely
rare as a four-leaf clover
ultrarare
superrare
exceptionally
one in a million
rare as hen's teeth
uncommon
unique
ultrararefied
rareish
semirare
rarer than hens' teeth
rocking horse shit
remarkable
rare as rocking horse shit
seldomness
unheard-of
as if by magic
attenuate
antrin
rarity
geason
incomputably
feat
rare
rarefactional
hellacious
rarefiable
inconsiderably
rareness
nonmiraculous
out of the way
unusual
horribly
extraordinary
unexampled
exceedingly
uncategorizably
uncommonness
unorthodox
superextreme
unwontedly
motherfucking
extremely
rotten
absurdly
motherfreaking