Specifically, one who takes the charge and management of funerals.

An individual whose business is to prepare the dead for burial and to arrange and manage funerals.

one whose business is the management of funerals

There was a short series of comic books based on the Undertaker. It focused mostly on his (kayfabe) background. It was produced by the now defunct Chaos!

a mere string of puns -- giving no idea of the true spirit of the author

one who takes up another's quarrel

One who stipulates or covenants to perform any work for another; a contractor.

One who undertakes; one who engages in any project or business.