"Dash it all" is an exclamation that expresses frustration, annoyance or disappointment. Synonyms for this expression can include "darn it," "blast it," "drat it," "rats," "oh bother," "shoot," or simply just "damn." These words can be used interchangeably to convey frustration or disappointment when something does not go as planned or when an unexpected obstacle presents itself. These phrases can be used in various situations, such as in conversations with friends or family, when dealing with a difficult co-worker or customer, or when facing a personal challenge. In any case, these synonyms can add a touch of character and emphasis to one's language.