immutable
unchanging
Roots
- -able / -ible: able to be, fit to be, or worthy of
- im- / in- (not): not or without
- mut: change
Other words with the mut root
- immutability: unchangeability
- mutability: capacity for change
- mutable: able to change
- mutant: changed from the usual form
- mutate: to change form or character
- mutation: a change or alteration
Immutable means not mutable: not able to change.
The deadline felt immutable, no matter how politely students asked.