The word "gater" may not have as many synonyms as some other words, but there are still some options available. One possible synonym is "gatekeeper," as both words refer to someone who controls access to a certain area or resource. Another option is "security guard," which is similar to gatekeeper but specifically refers to someone who provides security and protection. "Bouncer" is a more informal synonym for gater, often used in the context of nightclubs or other entertainment venues. "Watchman" and "sentinel" are also possible synonyms, suggesting someone who keeps watch over a certain area or object. Regardless of the synonym used, the role of a gater or its equivalent is an important one in ensuring safety and security.