The slang phrase "wert up" can be a greeting, an affirmation, or an expression of agreement. Some synonyms for "wert up" could include "what's good," "how's it hanging," "yo," or "hey." These phrases are often used among friends or acquaintances as a casual way of starting a conversation or acknowledging someone's presence. Other synonyms might include "that's right," "absolutely," or "indeed," which convey agreement or approval. The use of slang varies by region and age group, but regardless of the specific phrase, the intention is to establish a common connection or bond with the person being addressed.