1. To annoy someone and bring them down whilst they're in a good mood 2. To annoy someone and bring them down whilst they're high
1: "This guy's annoying the fuck outta me, he's totally harsh my mellow!"
2: "Like duuude, this guy just came along and was screaming at me and dude, whoa dude HE TOTALLY HARSH MY MELLOW man!"
A harshmallow is a rare combination of two food items to create one, a common practice amongst high people.
A harshmallow is a marshmallow dipped in hummus.
This particular combination was discovered by a female, but the term was coined by a member of the male species because everyone knows girls are stupid.
girl: Mannnnnnnn.... you know what would reallyyyyyy hit the spot right now...... some marshmallowdipped in hummus.