The words for unable to be fixed are uncorrectable, irremediable, irreparable, or incurable.
The word for unable to be "corrected" (as in made to conform) is incorrigible.
The likely word is the adjective insurmountable.
The word is insatiable, or the less common unappeasable.
The word is unavoidable or inevitable.
something that cannot be avoided = inevitable
invisible
The adjective is indivisible.
unavoidable
To recover something, or to retrieve it.
Deaf
It means to replace something, with something else that is equivalent.
Alternate. substitute (verb)
Yes, the word 'substitute' is a noun, a singular, common, abstract noun; a word for someone or something that takes the place of another. The word 'substitute' is also a verb (substitute, substitutes, substituting, substituted). Examples:Noun: Salsa is a good substitute for tomatoes in a sandwich.Verb: Ms. Lincoln will substitute for Ms. Washington while she is on her honeymoon.
The word substitute can be a verb and a noun. The verb form means to use something in place of something else. The noun form is a replacement for something which does a similar thing.
Synonyms include flawless or ideal.
Something that is lost and then found is recovered.