To "high-hat" one is 1) to scorn the individual, to demonstrate open disdain. 2) to melodramatically display lack of interest. 3) to be pompous; escpecially, to dismiss.
"Marjorie Kinnan Rawlings’ maid says the reason you were buried in an unmarked grave is you high-hatted the people of Eatonville. You were uppity."