Pro 5:3-6 For the lips of a loose woman drip honey, and her speech is smoother than oil; but in the end she is bitter as wormwood, sharp as a two-edged sword. Her feet go down to death; her steps follow the path to Sheol; she does not take heed to the path of life; her ways wander, and she does not know it.
There are apparently a variety of ways to look at these verses. The first that came to my mind was the idea of a woman enticing a man into adultery. It probably sounds like a good idea at the time, but it is not. A woman like this is referenced in Proverbs 2:16-17 and in chapter 7.
My other commentaries discuss this as a woman leading a man away from God and into idolatary. "Loose" is translated as "strange" in the KJV and would reference the women from other nations that tempted Israel into worshiping other Gods. This is still temping others into adultery, only this time it would be with God. Israel had this problem a lot!
In Chapter 9, this type of woman is also contrasted with Godly wisdom. So we could take it as verses regarding worldly wisdom. The wisdom of the world is enticing! It sounds so logical and pleasing. So easy to follow. As we know though, that's not the good wisdom. Good wisdom comes from God.
The first time wisdom is mentioned is when Eve decides she wants some, only she wants worldly wisdom. Look at the consequences. In these verses from Proverbs, we see this wisdom is still just as enticing. And those on the wrong path seek it, stumbling and never realizing it. Her ways wander, and she does not know it.
I think it references all of the above. Adultery in the simplest sense is in line with worldly wisdom - what could the harm be, many ask. And certainly, turning our backs on God and engaging in that type of adultery is also "normal" in the world today. Our drive for normal will take us down the wrong path, and we don't even know it.