Pronunciation: [wɒz ˈʌp] (IPA) 
The phrase "was up" is a relaxed version of "what's up." Its spelling is based on informal pronunciation, with the "t" in "what" often being dropped. In IPA phonetic transcription, "was up" would be written as /wʌz ʌp/. The first syllable "wʌz" uses the "u" sound as in "up," while the second syllable "ʌp" uses the "uh" sound as in "but." Overall, "was up" is a casual greeting commonly used among friends.
The term "what's up" is an informal greeting used to inquire about someone's well-being or ask about the current situation. Its etymology can be traced back to African American Vernacular English (AAVE) and has roots in various African American communities in the United States.
The phrase "what's up" emerged during the mid-20th century and gained popularity in the 1960s and 1970s. It initially appeared in African American cultural contexts as a way to greet one another informally. The exact origins and specific contributors to its development are difficult to determine since language evolution often involves communal contributions.
Over time, "what's up" became more widespread and entered mainstream American English, with many embracing it as a casual greeting. It has since spread internationally, becoming a popular and familiar phrase used in informal conversation.
