minimum
minimal
worst-case
leastest
noniterable
unissuable
nonissuable
unconsignable
ultrarare
uncanted
unriskable
rare
last
nonminimum
unpursuable
rarer than hens' teeth
unexcogitable
deadpan
subviable
noniterative
rare as a four-leaf clover
suspensory
uncommon
superrare
unlikely
unminable
subextensive
retrieveless
nonpotential
untriable
unevadable
unassumable
noninfallible
semirare
rareish
uncantilevered
phantom
geason
rare as rocking horse shit
unable
unpainstaking
noncantilevered
foggiest
underassured
nontethered
undiffusible
noncondensible
unhewable
nonpossible
unostensible