The phrase "wait on" is commonly used to refer to providing service or assistance to someone. However, there are several synonyms that can be used interchangeably to convey similar meanings. These include "attend to", "serve", "assist", "aid", "help", "support", "cater to", "be at the disposal of", "be on hand for", "take care of", and "look after". As with any synonym, the choice of word will often depend on the context in which it is being used and the speaker or writer's personal preference. Overall, these alternatives to "wait on" allow for more variety and creativity in language expression.