The phrase "rid off" is commonly used to indicate getting rid of something undesirable. However, there are several synonyms that can be used interchangeably, depending on the context and level of formality needed. Some of the synonyms for "rid off" include "eliminate", "dispose of", "remove", "discard", "jettison", "purge", "expel", "eradicate", "exterminate", "annihilate", "obliterate", and "erasure". Choosing the right synonym depends on the situation at hand. While the word "rid off" may be used informally, some of the synonyms may be more formal or technical in nature, and better suited for a professional setting.