The phrase "lose one shirt" means to suffer a substantial loss, especially financial. Some synonyms for this phrase could be "lose one's pants," "go bankrupt," "face financial ruin," "take a hit," or "be left in the red." Other similar expressions include "fall on hard times," "hit rock bottom," "be wiped out," or "run out of steam." These expressions suggest a significant negative impact, either financially or psychologically, and emphasize the severity of the loss. Whatever the situation may be, losing one's shirt is always a big deal, and it is important to seek help and support in times of need.