EXCLUSIVE

Nobody calls popcorn "pop" ... is the basis of a lawsuit the Michael Jackson estate has filed against a website using MJ's name to hawk popcorn.

MJ's estate has set its sights on KingOfPop.com ... a website that popped up in 2012 after buying the domain name of a former Michael Jackson fan website.

The estate claims the site tried to defend its use of the popular MJ moniker by saying the word "pop" is a "nickname for popcorn products." The estate says that's BS because "pop" is only a nickname for soda ... in certain parts of the country.