The word "staker" can be used in a variety of contexts, but if you're looking for synonyms, there are several options available. One possibility is the word "gambler," which can refer to someone who takes risks in the hopes of winning money or other rewards. Another option is the word "bettor," which specifically refers to someone who wagers money on the outcome of a game or event. Additional synonyms for "staker" might include terms like "punter," "risk-taker," or "speculator." Whatever word you use, it's important to keep in mind that the activity being described typically involves some level of uncertainty or risk.