In a battle of wit during discussion on public forums, message boards, fb groups.. etc. an Ivanism is considered to be a truly weak response of the highest degree. A weak and unbalanced retort in which extreme cases of butthurt are revealed. An Ivanism is also known as a euphemism to the expression "foot in mouth" which in many cases may come back to haunt person (who in lost train of thought or just out of plain stupidity blurts out said Ivanism) at a later time, even much later.
Some Ivanisms are so epic in content that they warrant being saved and stored for future/educational purposes.
Littledick: Your newest entry attempt on UD does not embarrass me in the slightest, and to prove my point I will be sure to look it up and click on "DO NOT PUBLISH" for "I am a Senior Urban Dictionary Editor, that means I am God.... bow before me!"
Bigdick: I may not get my entry accepted into Urban Dictionary, but you have just given me this most precious moment for which I am eternally grateful. You not only gave me the perfect example for my newest entry, but your latest shriek has got to be your greatest Ivanism yet.
Thank you, Mr. Senior Editor @ Urban Dictionary, your inspiration is greatly appreciated and I have decided to give it another shot.