curable
hard
sunbaked
tough
toughened
Philistine
abandoned
acclimated
acclimatized
accommodated
accustomed
adapted
adjusted
annealed
backed
brazen
calcified
callous
calloused
case-hardened
cold
cold of heart
coldblooded
coldhearted
conditioned
conscienceless
crusted
crusty
crystallized
experienced
familiarized
flinthearted
flinty
fossilized
granulated
hard of heart
hard-boiled
hardhearted
heartless
hornified
impenetrable
impenitent
impervious
incrusted
indurate
indurated
insensible
insensitive
insolent
inured
lapidified
lost to shame
gardened
pardoned