The oldest records on the subject are practical, not philosophical. Date, word as transcribed, circumstances of utterance. The record-keepers who compiled them were not asking where the words came from. They were asking when.
The philosophical questions arrived later and were largely abandoned. What had the child carried the word from? What world did the word name? These questions produced answers that disagreed with each other and with the records, and so the records eventually outlasted them.
What the practical people said, and passed down, was simpler: the word is prior to the child's knowledge of the world. Everything the child learns after is, in some sense, an attempt to find what the word already knows. You cannot teach the word to anyone. You cannot translate it. You can only write down when it appears, and in what presence, and over a long time see the pattern.
Some children found the pattern early. A girl in the coastal records knew her word named the feeling of a door closing in another room while you are still awake, and she knew this at five, when she lay in bed and heard her father leave. She stopped saying the word after that. The record-keeper noted it: Last occurrence, March 14. Certain now.
Most took longer. Some spent sixty, seventy years in the work of paying attention, saying the word into various light and weather and grief, listening for the interior response that meant: here. Closer.
The notebooks were kept, in the end, for that entry. The record-keepers waited years to write it. Certain now. Two words in their notebooks for a lifetime in the subject's.