“SMT" on Instagram typically stands for "Something." SMT meaning in text is a common internet slang abbreviation used to quickly convey the idea of "something" in a casual or informal context. People often use such abbreviations in comments, captions, or messages to keep their communication concise and informal. Other meanings of “Send me this”, “Sucking my teeth”, “So Much Trouble”, “Social Media Team”, “Saturday Morning Test” and more.