Bonhoeffer said, "when you read the Bible, you must think that here and now God is speaking to me."

A student of his said that he taught them to "read the Bible as it was directed at us. Not something general, not something generally applicable, but rather with a personal relationship to us."

Drawing upon that, another meaning for "the word of God" is, or perhaps should be, God condescending to make Himself and his will known to us in a most direct and personal way. And for that to occur we need help.

John 16:12-15 speaks to this. "But when he, the Spirit of truth, comes, he will guide you into all truth. That is why I said the Spirit will take from what is mine and make it known to you."

You're right, our interpretations can go wrong. That's why the counsel of mature believers (spoken in person, through sermons, the arts, etc.) is so important. Their lives and actions demonstrate that the "word of God," means they've actually experienced Him and not just His teachings.

Part of my senior paper in college (a conservative university) included a section on defining the phrase "Word of God." Sadly, I think the phrase transcends scripture (yet includes scripture).

"God's Word" is also includes when God whispers to me. In my research, I found a story about a husband and wife who would daily read scripture together, spend some time in prayer together. Then they'd write down whatever they agreed God had spoken to them. That would become "scripture" for them. They treated it as "God's Word."