adj. Great, good
interj. Used as an exclamation of joy, approval or astonishment.
"Kigi" is derived from an exclamation in either Mortal Kombat or Street Fighter; one of the characters would shout, "KIGIANANOOOO" while executing some killer move.
Person 2: It's pretty kigi.
Person 1: I just found a million dollars!
Person 2: Kigi!