The term "last resort" refers to a situation or action that is considered as the final option, when all other alternatives have been exhausted. It implies a desperate measure taken only after trying everything else, and it suggests that the outcome may not be favorable. The phrase can also imply a sense of resignation or acceptance that things cannot get any worse, so why not try this one thing that might work? Overall, "last resort" is used to describe a final effort made when all other options have failed.