BTW is an initialism that stands for "By The Way" and is used in text, chat and speech. Learn the history, other meanings and how to use BTW in different contexts with examples. BTW is a written abbreviation for by the way, used to add extra comments or information in emails or texts. Learn more about its usage, pronunciation and translations in different languages. By the way: used esp in emails, text messages, etc.... Click for English pronunciations, examples sentences, video. One such commonly used acronym is BTW, which stands for “ By The Way .” BTW is an expression that is used to introduce additional or supplementary information into a conversation. It serves as a transition to a related topic or a side note that might be of interest to the listener or reader.