Soda/ˈsəʊdə/ Definition 1 of 4Pro Tip 1/3Informal Usage Soda is a casual term, not usually used in formal writing. Let's grab a soda after class. Pro Tip 2/3Cultural Variance In some English-speaking regions, 'soda' can be called 'pop' or 'coke'. Do you call it a soda or a pop? Pro Tip 3/3Healthy Diet Soda is often associated with unhealthy eating habits. Trying to avoid soda to cut down on sugar.