What does it mean to univalve a cast?

"Univalve" is not a standard term used in the context of casting. It's possible you've heard this term mispronounced or confused with a similar one.

Here are some possibilities for what you might have meant:

* "Un-valve" a cast: This could be a mispronunciation of "Un-wrap" a cast. This refers to the process of removing the plaster or fiberglass cast from a limb.

* "Univalve" as a synonym for "Univalve shell": This is a type of mollusk shell that has a single valve (i.e., one piece) like a snail shell. It's unlikely this has anything to do with casting.

If you can provide more context or a different spelling of the term, I can provide a more accurate answer.