Satoshi Millionaire is one, who has 1 million Satoshi, i.e. 0.01 BTC.
There was a time when new entrants wanted to reach goal of 21 BTC, i.e. one in a million. Then it became Satoshi Billionaire, i.e. 10 BTC. Then 21 million club, i.e. 1 BTC. Now, owning 1 BTC is difficult and being a Satoshi Millionaire is the new goal.