"TTFN" is an abbreviation of the informal phrase "ta ta for now," meaning goodbye for the moment. If you're looking for some synonyms to use instead of "TTFN," there are many other ways to say goodbye! For instance, you could use "farewell," "adieu," "see ya," "later," "take care," or "goodbye for now." Other similar phrases might include "catch you later," "until we meet again," "bon voyage," or simply "bye." Whether you prefer a casual and friendly tone or something a bit more formal, there are plenty of options to choose from when it comes to saying goodbye.