Those aren't called milk because they're a substitute for anything, they're called milk because that's the English word for a cloudy translucent liquid. See al

Those aren't called milk because they're a substitute for anything, they're called milk because that's the English word for a cloudy translucent liquid. See also milk glass, milk thistle, and milk of magnesia. Speaking for myself, I drink almond milk because it tastes better than cow milk.