Lyric discussion by Amaranthian 

Cover art for Liar lyrics by Nine Inch Nails

pinion7, I find this song has quite a different meaning when I listen to it.

In the first verse, he speaks of "her" as an evil that let's unsuspecting people into her life and destroys them (in a mental or emotional sense), and then sends them out into the world to breed more hate and deception: "Seeds from a thousand others drip down from within."

In the chorus, it seems as if he is praising her and what she has done for him, but in a mocking sort of way. Let me clarify this: he is being sarcastic in his praises, saying she is precious and beautiful (how she makes him feel about her at first), but he calls her a whore and a liar (what she really is "underneath the skin"). In the third line of the chorus, "My disease, my infection," he is proclaiming her to be the reason he is so disgusted with who he is. In essence (in the final line of the chorus), he concludes that he is truly impure and has been corrupted by the "reptile" or the "liar."

In the first two lines of the second verse, he explains how "devils" praise her and how "angels" are hurt by him. This is showing that the reptile is deceptive, she has twisted people around her finger so that she is thought of and seen as good, while he is seen as the evil one. In the next two lines, he realizes he has reached a point where he can no longer recover from the wounds the reptile has inflicted in him. He is falling into despair and the only way he can lessen the pain is by hurting others.

The chorus repeats three times through the rest of the song. It climaxes at the end, you can hear the pain and emotion in Trent's voice: he is pouring his whole heart into making the truth of the reptile known.

This is just my take on it, line for line. If you have a different perspective on it, or think my view is flawed, feel free to say so.