"Gat it on" is an informal expression that is often used to describe the act of engaging in sexual activity. However, it is important to note that this term can be considered crude and offensive by some people. If you are interested in finding alternative words to use instead of "gat it on", there are plenty of options to choose from. Some synonyms for this phrase could be "get intimate", "make love", "have sex", or "engage in sexual activity". These words are more polite and respectful, and can be used in a variety of settings, from casual conversations with friends to more serious discussions with partners.