"Boken er kjedelig."

Translation: The book is boring.

[AlexValver5]

Leon.. I confess that I couldn't understand your phrase (when trying to translate it)

[pugfids]

I have to hop around on one foot now. It was so boring i kjed e lig!

[FLchick]

This must be about Crime and Punishment. The crime was Dostoyevsky writing it and the punishment was having to read it.

[TheMalpaisLegate]

What I thought that was a really good book

[Aleyzee]

Kjeder meg means I am bored?

[hmada993]

Shouldn't it be kjedelige since boken is definite?

[otsogutxi]

Kjedelige is the plural form

Bøkene er kjedelige ~ the books are boring.
Boken er kjedelig ~ the book is boring.

I hope this helps! If you have more questions, feel free to ask me:)

[fveldig]

You could say "Den kjedelige boken er kjedelig", so you'd use the indefinite form when it's not in front of the noun.