The term Taikyoku used for the three most basic of all karate kata, seem to have reference to the idea of "noble" or "intense," maybe portraying "the highest extreme."
Below are videos of these three beginning kata (Taikyoku Shodan, Nidan and Sandan). Some martial arts groups have dropped these kata, seeing them as too simple, but the Taikyoku stand in AKDS as our most fundamental kata for all practitioners. Performed by 5th Dan Jeremy Crook, the standard three are followed by two "weaponized" variants developed for additional practice on muscle chaining and body condition.
When translating martial arts terms, the meanings of the names of the kata are especially ambiguous. Harada Sensei has stated that even Japanese karate practitioners (including himself) aren't quite sure just what some of them mean. Theoretically many of them are based on famous duels that occurred in the distant past, and theoretically some of the names may have something to do with the circumstances of those duels.