The phrase "be dependent on" means to rely or count on someone or something for support, help or guidance. There are several synonyms for this phrase which can be used interchangeably in a sentence to convey the same message. For example, "rely on", "lean on", "depend upon" and "count on" are all synonyms for this phrase. Similarly, "trust", "bank on", "rest on" and "repose on" can also be used to express a similar idea. Moreover, phrases like "be at the mercy of", "be subject to", and "be influenced by" are also synonymous with "be dependent on".