What do you call the big misshapen thing that you carve ginger (the spice) out of?

a root

A corm.

I never knew that. I thought it was root too. Well spotted.

Yeah, I married a biologist. :)

I always thought it was a rhizome.

Ginger is a rhizome and even though I’m not married to a biologist, I know this for a fact!

Corms are rhizomes. Or, rather, corms use the mechanism of a rhizome, with beneficial soil bacteria.

In Chinese it’s called a hand, based on the shape of a decent sized piece of ginger.

SRM