Theorem made me try lemma: 99% advanced, <1% basic, <1% intermediate.

nice.

A new challenge for HN: Find a pair or series of words that are synonymous but have the largest variance in Advanced readers. Bonus points if you can provide a progression of words from basic to advanced.

"black hole": 57/37/5

"gravitational singularity": 4/7/88

Maybe cheating, but:

"middle step": 18/43/38

"lemma": <1/<1/99

"endofunctor" has the same numbers, and so does "homomorphism".