Regional Note: Generic terms for carbonated soft drinks vary widely in the United States. Probably the two most common words competing for precedence are soda, used in the northeast United States as well as St. Louis and vicinity, and pop, used from the Midwest westward. In the South any soft drink, regardless of flavor or brand name, is referred to as a Coke, cold drink, or just plain drink. Speakers in Boston and its environs have a term of their own: tonic. Such a variety of regional equivalents is unusual for a product for which advertising is so aggressive and universal; usually advertising has the effect of squeezing out regional variants. On the other hand, there are so many types and flavors of soft drinks that perhaps no single generic word has ever emerged to challenge the regionalisms.
The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.