false, worthless, empty, hollow
虛 centers on a lack of substance or truth: something empty, hollow, false, or worthless. The meanings all point to an absence of real content or value.
虛 is the traditional form of 虚. It combines 虍 (tiger stripes) with 丘 (hill), suggesting a hollow or empty hill. The idea of emptiness extended to falsehood and worthlessness.
The outer 虍 suggests tiger stripes, and the inner part looks like a hollow hill. Imagine a tiger's den inside an empty hill: it looks fierce but is actually hollow and false.
For キョ, imagine a hollow, worthless old car that you need to 'key' to start: key -> キョ, and the car is as empty as the kanji's meaning.