What is the Easiest Language?

It's Toki Pona, but...

In a prior article/script, What is Toki Pona? in 3 minutes, I called Toki Pona "the easiest language." I also doubled down on this claim when I explored the history of claims about how long it takes to learn Toki Pona. It's fair to call this claim contentious- at a minimum, there is not much evidence to make this claim, and the evidence that exists is lacking rigor and scope.

Rather than telling you why this claim is strictly true, I'd like to instead explain what it means for Toki Pona to be the easiest language.

What does "easiest language" mean?

What do I mean when I say "easiest language"?