To be idiotic or retarded in an unintentionally manner.
"Look at that guy he is such a mongxiong!"
"Did you see Brandy's Right Here music video? She looks so mongxiong in it!"
When one is late for an appointment or meeting. Or someone who is just generically slow in doing anything.
"You snail! You're always late!"
"Could you eat a lil faster? You're such a snail!"
The ecstatic and thrilling feeling you feel when:
1) You see someone extremely hot.
2) Someone you love does something really sweet or good to you.
"Omg that guy's so fucking hot I'm gonna melt!"
"Last night, I melted when my boyfriend did the sweetest thing ever!"