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 slang word meaning error means-something bad you have done like me saying " mate you have just made a awful error
novice
postulates
The likely word is "easily" (synonyms are simply or freely).
mistake
Mistake
A typographical error.
error