The phrase "in habit of" means accustomed to or frequently engaging in a particular behavior. Some synonyms that can be used in its place include "accustomed to," "used to," and "familiar with." Other possible alternatives include "prone to," "regularly engaging in," "in the practice of," and "habituated to." In addition, some similar phrases that convey similar meaning include "in the habit of doing something," "in the custom of," and "in the tendency of." Depending on the context in which it is being used, different synonyms may be more appropriate or effective.