The phrase "blow lunch" is a slang term that refers to vomiting or throwing up. There are many synonyms for this phrase, including "barf," "puke," "throw up," "chunder," "hurl," "upchuck," "regurgitate," and "spew." While this may not be the most pleasant topic, it is important to have a wide range of vocabulary to accurately and effectively communicate. In professional and formal settings, it is best to avoid using slang terms and instead opt for more traditional terms such as "vomit" or "throwing up." However, in more casual settings, using synonyms for "blow lunch" can add some humor and variety to the conversation.