The phrase "four three two one" essentially means a countdown. It is often used in space launches or other events where timing is crucial. However, if you're looking for some synonyms to mix up your countdowns, here are a few options: 1. T-minus: This is another space-themed option that simply means "time remaining until launch." 2. Commencing: This word has a more formal connotation and could be used to begin a ceremonial event or performance. 3. Initiate: Similar to "commencing", this word suggests the beginning of an important task or process. 4. On your mark: This phrase is often used in races and competitions to signal the start of the event. 5. Start your engines: Another racing-related option that could be used to begin an activity or competition. There are many other creative ways to countdown or signal the start of an event or task.