What is a noun in your own words?
will give you

A noun is a person, place, or a thing. A proper noun is the name of something/someone and is capitalized. A common noun is just a general word for something/someone and is NOT capitalized.

A noun can be a person (Jeff), place (the park), thing (chair), or idea (going to the park).

in june, we will have been married for eighteen months. (i am assuming this is what you want? the sentence, as you have presented it, is grammatically incorrect--   you want it corrected, yes? )

major league baseball

explanation:

jack roosevelt robinson broke the color barrier in major league baseball.as he was the first african american to play in the major leagues, jackie robinson became the target of racial abuse. jackie robinson is referring to the historic event, harlem riot.