This is a word from the Star Wars Movie: The Empire Strikes back. It means "Eat shit." (I think.) You can hear the word uttered when C3P0 is walking in the cloud city and a similar driod appears behind a door and tells C3p0 echuta.
Person A: "Well hello there! Nice to see a familiar face!"
Person B: "Echuta."
"E chuta!" is an untranslatably rude Huttese expression used on C3PO by another protocol droid in "The Empire Strikes Back," shortly before the luckless golden robot is blasted apart by stormtroopers. In context, it appears to be the rough equivalent of "fuck/piss/sod off."
"Can't we put away our blasters and negotiate calmly?"