Antonyms for "chance upon" include miss, overlook, avoid, bypass, neglect, and ignore. These words imply a purposeful action, rather than the accidental discovery that "chance upon" conveys. To miss something is to intentionally overlook it; to avoid something is to purposefully evade it. To bypass something is to intentionally go around it, and to neglect it is to intentionally ignore it. These words highlight the deliberate act of not encountering something, rather than the chance encounter implied by "chance upon." By knowing these antonyms, one can better understand the complexities of language and the multiple ways in which we can convey meaning.