Is any word untranslatable?

Not long ago I was given the task of presenting an untranslatable word at an event at the Free Word Centre, where I am translator in residence. This interest in untranslatable words, which ties into one of the centre's new lines of inquiry, The Power of Translation, began last year with a blog that compiled untranslatable words from different languages. There were some fantastic words that would a

[Ditty]

tsundoku（積読）は翻訳不可能な言葉だと。