Conclusion:
- Satoshi Nakamoto is indeed the inventor of the concept "blockchain".
- Originally it was "block chain" later became one word as a noun we know today "blockchain".
- Satoshi Nakamoto invented the concept "block chain" in 31 October 2008
- Birth of the word "blockchain" happened on this forum bitcointalk around 2010
Hmm. I think Chaum, Stornetta, Beyer and Haber would take issue with this. Rightly so.
It would be accurate that Satoshi was the first to make a meaningful implementation of a blockchain, by combining that concept with several others he also did not invent.