Sorry, to nitpick, but I'm an electrical engineer. It's not wrong to call L the "live" wire; that's actually common terminology even though it technically stand's for "line."
However, N definitely does not stand for "negative." In a single-phase A/C power setup you generally have 3 lines: "line" (the black wire that will fuck you up); "neutral" (the white wire which actually has no voltage on it when disconnected but its used to complete the circuit to the power source); and "ground" (which is technically not needed for a the circuit, but is very important for safety measures).
A truly "negative" wire would only exist in a DC setup where it had some sort of static voltage below the reference ground voltage.