What does dd stand for?

Though the “best answer” was given, this site states otherwise:

Actually, it stands for ‘Copy and Convert’ and was renamed to dd only because cc was reserved for the C compiler! This is the authentic information I got from the man pages of our Unix-V7 on our university PDP 11.

Original mail at comp.unix.misc(usenet): The Unix Acronym List

Wikipedia (dd) asserts it was named after IBM JCL command DD which stands for Data Definition. I always thought it would mean data duplicate, though.

"dump data". JCL is irrelevant.