Antonyms for the word "regains strength" refer to the loss or deterioration of strength. Some possible antonyms for this phrase include "loses strength," "weakens," "declines," "falters," and "deteriorates." When an individual or organization loses strength, they may experience a decline in productivity, efficiency, or effectiveness. This loss can be caused by a variety of factors, including illness, injury, lack of motivation or resources, or external factors such as market changes or economic downturns. In contrast to regaining strength, these antonyms suggest a need for improvement or intervention to address the underlying causes of weakness and restore vitality and resilience.