The phrase "bump into" refers to an accidental meeting, where two people meet unexpectedly. There are several synonyms for this phrase, including "run into," "encounter," "collide with," "meet by chance," "stumble upon," "chance upon," "come across," and "cross paths with." Each of these phrases conveys the idea of an unexpected meeting. However, the degree to which the meeting was accidental varies. Phrases like "run into" and "collide with" suggest a more physical meeting, while phrases like "meet by chance" and "stumble upon" are less intense. Regardless of the exact phrasing used, all of these synonyms suggest an unexpected, chance meeting between two people.