efficaciter
From LSJ
τὰ δὲ πεπερασμένα πεπερασμενάκις ἀνάγκη πεπεράνθαι πάντα → and the product of a finite number of things taken in a finite number of ways must always be finite
Latin > English (Lewis & Short)
effĭcācĭter: adv.,
I efficaciously, effectually, v. efficax fin.