What is the common definition? (by common definition, I mean the definition most people associate with the term)
I have already told that to you and you ignored it.
To put it simply, it would be an entity in Euclidean geometry with no curvature, where the angle sum of a triangle is always 180 degrees, and with no principle curvature either.
Yes, but 2D doesn't mean not flat either.
You are claiming it is flat, the burden is on you to substantiate that.
And again, flat surface doesn't mean flat Earth as Earth is not the surface.
You have yet to provide counter-evidence... You have simply asserted it as fact.
GET THIS THROUGH YOUR THICK SKULL!!!
I don't need to provide counter-evidence to call your baseless claims baseless.
The burden of proof is on you.
If you want to pretend these sources back you up, PROVE IT!
Otherwise all I need to refute you is this one source:
en.wikipedia.org/wiki/Special:Random
Stop acting like a pathetic troll and grow up.