incurable

nouns

a person whose disease is incurable
is a type of (narrower)
a person suffering from an illness

adjectives

incapable of being cured
"an incurable disease"; "an incurable addiction to smoking"
is derived from
is derived from
antonym
unalterable in disposition or habits
"an incurable optimist"
is derived from
is similar to
not capable of being changed or altered
"unalterable resolve"; "an unalterable ground rule"