The phrase "in the habit" refers to a behavior or action that someone regularly engages in. There are several synonyms for this phrase, including "accustomed to," "used to," "prone to," and "regularly doing." These words can be used interchangeably with "in the habit" to convey the same meaning. For example, "She's in the habit of going for a run every morning" can also be expressed as "She's accustomed to going for a run every morning" or "She's prone to going for a run every morning." No matter which synonym is chosen, the message conveyed is that someone has formed a routine or behavior that they consistently engage in.