Unbudgeted refers to something that was not planned for in a budget. Other words that can be used to describe the same concept include: unforeseen, unplanned, unexpected, unanticipated, and off-budget. These words can be used interchangeably to convey the same meaning. For instance, if a company suddenly incurs huge expenses that were not planned for in their budget, they can refer to them as unbudgeted expenses. Similarly, if an individual decides to purchase an item that was not in their budget, they can describe it as an unplanned or unforeseen expenditure. These synonyms come in handy when one wants to communicate an unexpected occurrence that has financial implications.