There are numerous synonyms for the phrase "on a trip." Some of the most common alternatives include "traveling," "journeying," "exploring," "venturing," and "touring." Other options include "road tripping," "cruising," "sailing," and "flying." Each synonym can help to convey a slightly different connotation and add more variety to writing or conversation. Additionally, using a synonym can help to avoid repetition and keep the language fresh and interesting. Whether one is writing an article, describing a vacation, or simply discussing a recent outing, there are plenty of synonyms to use instead of "on a trip".