Immutable
adjective
not subject or susceptible to change or variation in form or quality or nature
“the view of that time was that all species were immutable, created by God”
Similar: changeless
Word family
immutableness
adjective
not subject or susceptible to change or variation in form or quality or nature
“the view of that time was that all species were immutable, created by God”
Similar: changeless
immutableness