"A wise man hears one word and understands two" I assume that the concept of word to mean collective words forming a statement, evidence-based facts, truths or a concept. When someone tells us, "Can I have a word with you?" we would expect an exchange of thoughts, ideas, and views that need to be settled by two adults. It's so important to not allow a day pass without having a meaningful conversation with the person. For example, the Bible of Scriptures is synonymous with "The Word of God". So, it means that when we read some portions of the Word of God, say, in Psalms, we begin to see in the lens of understanding that God is talking to us through the experiences of King David. We are deliberate in knowing more and reasoning with our minds. And then, internalize the words into our hearts and soul. Then, our actions follow this experience of wisdom. I think that's what it means to "hear a word and understands two."
That explanation never would've occurred to me. When I read the title my initial thoughts were maybe the word and its polar opposite? Either that or maybe reading between the lines? I'm going to have to think on this. Your explanation makes a lot more sense than anything I can come up with.