sporadic
uncommon
sporadicalness
rare
geason
unique
rareish
semirare
ultrarare
atypical
seldomness
remarkable
rare as a four-leaf clover
ultrararefied
rare as rocking horse shit
sporadically
periodically
rarer than hens' teeth
nonrare
rare as hen's teeth
common as pig tracks
sporadical
unusual
rareness
uncommonly
unregular
aestival
few and far between
episodic
estival
rarefactional
superrare
nonprevalent
not grow on trees
unprevalent
not uncommon
now and again
from time to time
at times
rocking horse shit
now and then
occasionally
on occasion
once in a while
different
one in a million
unusualness
dead donkey
exceptional
antrin
unwontedly
aleatorily
episodicity
occasional
attenuate
randomity
seldom
unfrequent
rarefication
historically
out of the way
grab bag
haphazardly
infrequent
willy-nilly
arbitrarily
foggiest
at random
every which way
strange
indiscriminately
randomly
raresome
once in a blue moon
offbeat
randomish
frequent
aleatorically
weird
noncommonable
roughly
out of the common
uncommonable
noncommon
spontaneous
regularity
shenanigans
commonplace
endemic
distinguishing characteristic
uncommonness
distinctive feature
peculiarity
freakish
rarity