@tchrist, I can't compare, but surely it takes more than his words and his conjectures to refute Larousse. The text is sloppy: he says (in comments) it is not a prefix but an
element or a
preverb, he mistakes Italian 'tacco' (heel) with 'tacca' (notch) he imagines the word recorded by Larousse, Oxford etc. 'dies a silent death' without leaving traces and 'hey, presto' he conjures up a new form from nowhere. I though you can't get worse than that. I pinged you since tomorrow I should award the bounty, but if you say you will post, I'll wait. —
user78549 3 mins ago