surely
A four letter word meaning not kosher is: tref
error Fault
What is a nine letter word meaning very tidy
The word pine can have that meaning.
A four letter word for error can be slip.
bare
abstain
surely
A common slang word for an error is "blunder" or "screw-up."
novice
postulates
The likely word is "easily" (synonyms are simply or freely).
mistake
Mistake
A typographical error.
error