Cadaver < lat. cadere?

Etymological dictionaries agree that the widely borrowed Latin
"cadaver" derives from "cadere" 'to fall', but they gloss over the
details.  Where's the -v- from?  I can't tell if this is simply
obvious--if you actually know Latin, which I don't--or genuinely
unknown.

Many perfect stems have -v-, but cadere has a reduplicating perfect,
cecidi.  Also, the perfect -v- doesn't appear in participle stems,
I think, which would be the most likely source to derive a noun
from.

So how _is_ cadaver formed from cadere?

--
Christian "naddy" Weisgerber                          naddy@mips.inka.de