unwashable means not washable; that cannot be washed. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
Etymology
From un- + washable.
adj
- Not washable; that cannot be washed.
noun
- Something that cannot be washed in the normal way without being damaged.“Unwashables, such as stuffed animals, should be stored in bags for at least 1 week until mites have died”