Gualicho: Outside the native ethnic groups of the southern cone, it is the name given to curses.
Example:
"Me hicieron un gualicho"="I've been cursed" (literal translation: "Someone put a gualicho on me").

Che: Interjection commonly used in Argentina (and other Latin American countries). It basically means "Hey" and in some contexts it could be interpreted as "Yo!" or as a "friend".
Example:

"¿Che, cómo estás?"=Yo, how are you?=Hey, how are you?=How are you, friend? (literal translation: "Che, how are you?" or "Che, how are you doing?")