To give something a word is to categorize it, abstract it, encourage its use – perhaps even for something so different the coiner of the word would not recognize it. Meaning drifts because the object itself drifts, but not everyone’s memory of the drift is the same. This is the root of miscommunication, even when nothing is veiled by the teller and the listener’s attention is undivided.
To be fully known by God – that is to speak to him without this divide of minds. When the renewal of ours is complete the words that pass between us will be so clear, so violently lacking in obfuscurity, beams of light may come from our lips to anyone within earshot.