Indeliberately means to do something unintentionally or without forethought. Synonyms for indeliberately include accidentally, unwittingly, unknowingly, inadvertently, by chance, haphazardly, thoughtlessly, carelessly, rashly, heedlessly, unpremeditatedly, spontaneously, impromptu, and impulsively. These words indicate that an action was done without any conscious planning or prior consideration and may imply that it was done hastily or without much thought. While indeliberately conveys a sense of unanticipated consequences, the synonyms listed here suggest varying levels of intentionality or absence thereof, providing a range of shades of meaning to choose from depending on the context and tone of your writing.