Tell me something I don’t know.
“Veggie” is babytalk; it’s evidence of the ongoing infantilization of American people.
BTW, I don’t use babytalk when addressing very small children. I have too much respect for them to do that.
Well, it’s used by adults in all English speaking countries now - watching British cooking shows, you’ll hear it all the time; so I guess they don’t consider it ‘baby talk’. At worst it’s just a relatively new slang word.