Can mean to get upset or to encourage someone
"I'm about to go off, this person behind me is standing too close."
Originally emerging in African American Vernacular English (AAVE) during the 20th century, "go off" initially connoted an explosion of emotion or action, often in a negative sense, such as losing one's temper or becoming excessively excited. It carried undertones of intensity and unpredictability, reflecting the volatile nature of the situations it described. Over the years, however, the term has expanded its range of meanings to encompass a broader spectrum of experiences. Today, "go off" can denote various forms of enthusiastic approval or success, particularly in the realms of music, fashion, and pop culture. For instance, a song that is particularly engaging or energetic might be described as "going off," indicating its ability to captivate and excite listeners.
Similarly, a person who delivers a compelling performance or makes a bold fashion statement could be said to "go off," signaling admiration for their charisma and confidence. This evolution highlights the dynamic nature of language and its capacity to adapt to changing social dynamics and communicative needs.