Not to be confused with holophrasis. A means of expressing more complex ideas but through single words. It's a very childlike (or childish) way of speaking. "Give!" "Want!" "Mine!" God gets it, so do our parents. But if you're reading this, hopefully you've grown out of the need to express yourself in such a simplistic manner. Think about the way a child expresses itself. Their whole body gets in on the word spoken. They point to the object in question or else clutch it to their chest for protection. I find that the opposite holds true for adults who speak "words without knowledge" in that there is no action coupled with the word(s) spoken.
"Of these things put them in remembrance, charging them before the Lord that they strive not about words to no profit, but to the subverting of the hearers." (2 Timothy 2:14, emphasis mine)
Paul writes to Timothy. The words we speak have the power to open up God's will for our lives and others. Nearly every time I've given out a word that lifted the hearer, I was not aware of it. In other words, I found out they were uplifted and encouraged only because they told me so. Think about all the times I (or you) made someone's day and yet never heard from them again. The depths of heart are not easily reached. But God knows. It says prophetically of Jesus that, "The Lord God hath given me the tongue of the learned, that I should know how to speak a word in season to him that is weary:" (Isaiah 50:4)
Voices, voids, avoirdupois
How hard is it to glean a kernel of truth from the thousands of words we hear everyday? I'm not talking about hearing something we've never heard, new words that point to definitions beyond what we already know. I'm talking about the heart depth of conversation that is several layers removed from the frivolity you only need eavesdrop a tad in order to witness. To the calloused and/or hurting soul, the right word(s) at the right time could be a lifesaver. I apologized again to a friend the other day because I felt led by the Holy Spirit to do so. Never mind that I'd already apologized for what I said a couple months prior, the wound evidently must've been refreshed. I didn't know this though. And I even tried to suppress the compelling, thinking it was just me dredging up the past. But no. My friend's heart was touched by what I said and it even led to deeper conversation than I was expecting. A win/win situation if I do say so myself. Think about what Paul says in his letter to Timothy: to the subverting of the hearers. What does this mean?
"Who is this that darkeneth counsel by words without knowledge?" (Job 38:2)
God asks Job. He's basically saying the same thing. When you speak but have no experience or love to back what you're expressing, you do the hearer a disservice. If only we knew the right words at the right time. Like a spiritual "writer's block" but for speaking. The only one, I believe, who knows just what to say and have the words touch the places they need, is the Holy Spirit.
"So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it." (Isaiah 55:11)