1. One who mongs dongs.
2. A person who is known to be an annoyance to a particular group of friends, who secretly dislike said person.
3. Less used insult similiar to "dick-head."
A Humangalong Dongalong (hu-mun-guh-long donga-long) is another word for a joint, spliff, doobie, etc. and is largely considered as one of the most fun things to say
Hey Otto, wanna strap up another humangalong dongalong?