means The art or act of applying pigment to a surface to make an image, or the finished image itself.

from From 'paint,' which came through Old French 'peindre' from Latin 'pingere,' meaning 'to paint, embroider, or decorate.' That same Latin root quietly seeds 'picture,' 'pigment,' and 'depict' — all members of one ancient family obsessed with putting color where there was none. The '-ing' is the plain English suffix that turns an act into a thing, so 'painting' is, literally, 'the doing of pingere,' frozen on a wall.