The term "spur of the moment" refers to a decision or action made on a whim or impulsively without much thought or planning. Synonyms for this phrase include impromptu, spontaneous, unplanned, extemporaneous, and ad hoc. These words all describe a situation where a decision or action is made suddenly or without much preparation. While spur of the moment decisions can be exciting and adventurous, they can also lead to regrettable outcomes if not carefully thought through. It's important to weigh the consequences of any impulsive actions and consider the potential outcomes before making a decision.