The phrase "in less than no time" is commonly used to describe something that happens very quickly. Some common synonyms for this phrase include "in a flash," "in the blink of an eye," "in an instant," and "in no time at all." Other synonyms for this phrase might include "quickly," "swiftly," "rapidly," "speedily," and "instantaneously." These words can be used to add emphasis to a statement or to describe a situation that happens very quickly or suddenly. Whether you are writing a story or simply trying to convey a sense of urgency, using synonyms for "in less than no time" can help you get your point across effectively.