1.) Word used when a certain accomplishment or goal is met.
2.) To tell a person to have sex with someone; usually screamed out loud. Using the word this way can also be used as an insult, pertaining to someone who is with another person.
1.) Nice, I passed my global history test!! GITSUM!!!!!
2.) Jim: Hey Thor, look at Marty helping that old lady across the street.
Thor: Hey Marty, GITSUM!!!
Marty: What's WRONG with you?