An Ukrainian (іди нахуй) and Russian (иди нахуй) vulgar expletive, usually translated as "go fuck yourself" or simply "fuck off". Can be rendered in various ways using the Latin alphabet, with the most common being 'idi nahui' (with 'idi nahuj' close behind).
Ukrainian "іді нахуй" is a part of transliteration of Russian "Русский военный корабль, иди нахуй" ("Russian warship, go fuck yourself"). This quote was used on a big amount of Ukrainian posters. One of those, with yellow text on blue background with big stylized "іді", later became a meme after being cropped to just "іді нахуй".
