根

1. noun root (of a plant)
2. root (of a tooth, hair, etc.); center (of a pimple, etc.)
3. root (of all evil, etc.); source; origin; cause; basis
4. one's true nature
5. (fishing) reef

こん

1. noun stick-to-itiveness; perseverance; persistence
2. radical (esp. one that tends to ionize easily)
3. mathematics root
4. Buddhism indriya (faculty of the body having a specific function, i.e. the sensory organs)