While an Erfworlder will instinctively understand "kill" and "death" to have the same meaning, it is not a normal part of their vocabulary and they will find it vulgar if they hear it from someone else, like a Stupidworlder.
Croaked units leave bodies, which exist as physical objects for a short time after croaking. Bodies disappear at the start of the next turn that their side has, unless moved/claimed (e.g. uncroaked, reanimated as golems, eaten, used for something else like the teddybearskin rug and mounted gwiffon head in Parson's room)Erf-b1-p035. In the event that their side is eliminated, unclaimed bodies disappear at the next nightfall.
Due to the facts that Wanda had to retrieve the body of Manpower Erf-b1-p3 and later said that they had to capture Ossomer, rather then croak and drag the body over to GK's hex afterwardsErf-b2-p6, there is speculation that moving a dead body from hex to hex causes it to be impossible to uncroak/decrypt. The evidence either way is weak though as somebody was going to have to retrieve Manpower's body so it may as well have been Wanda who could uncroak it immediately; in Ossomer's case, Ansom wanted Ossomer alive to try and turn him, Wanda decided she wasn't going to bother and decrypted him instead.