An exclamation, often done with a southern dialect ("Mach Man" Randy Savage/Hulk Hogan), it stresses a fundamental flaw in someone else's logic, especially in regards to matters of patriotic validity.
Some Guy - I feel that capitalis has done more harm than good to our country
"True Patriot" - Whoa there, Brother! I don't know where you come from but here in America, we tend to do things right, if it ain't broke, don't fix it!
A male who has a preference for platonic "fraternal sibling" relationships with women as opposed to sexual relationships.
The "little brother" may not necessarily reject a sexual encounter with a woman with whom he has developed a "fraternal sibling" relationship, but it is not the primary motivation for initiating or continuing the relationship and generally not the desired outcome.
"Don't start unless you're up for it all the way. I don't need another littlebrother".