The term "most time-saving" refers to something that saves the most amount of time. The antonyms of this word would be phrases or words that suggest the opposite, indicating something that wastes time, takes longer or needs more effort. Some examples include "time-consuming," "inefficient," "slow," or "wasteful." These antonyms can be used to describe actions, processes or products that require more energy, resources or attention than is necessary or appropriate. Using these antonyms can help people create a more efficient approach to their daily work, improve productivity and increase effectiveness in any given activity.