What does the French "Can" mean here?

The way I've reconstructed it, nothing.

The story that I have heard is that the pronunciation of Latin slowly changed from country to country, reflecting the pronuciation of the national language of that country. This is reflected in the two most common liturgical Latins of today, the Italianate, characterized by the [kw] pronunciation of qu, the [tsh] of c before i, e or y and the softening of g before the same vowels; and the German, characterized by the [kv] pronunciation of qu and the [ts] of c before i or e. The g is always hard in German church Latin.

The worst offenders in this were the French who pronounced quamquam [kãkã]. This pronunciation was later spelled cancan and came to mean a disreputable performance.

That's as far as the story went. The leap from there to the name of the dance is all mine, as far as I know.