隐形
yǐn xíng · HSK 7
invisible
👻 隐 hide + 形 shape = hidden-shape = invisible
隐 means hide or conceal; 形 means form or shape. A form that is hidden is one nobody can see — invisible. The same 形 shows up in 形状 (shape) and 图形 (figure).
形 — open frame 开 + hair/pattern 彡
形 combines 开 (originally a phonetic element suggesting the sound) with 彡, a radical depicting fine lines, hair, or decorative strokes. The 彡 part conveys the idea of visible markings or surface appearance, giving 形 its core meaning of 'shape' or 'form.' Over time it broadened to cover physical figure, appearance, and abstract form.