There are various synonyms that can be used in place of the word "longshot". Some of these include "dark horse", "underdog", "outsider", "hopeful", "long shot", "remote possibility", "unlikely candidate", and "outside chance". These words portray the idea of something or someone being a risky bet or an improbable choice. They all capture the essence of uncertainty and unlikelihood, making them suitable to describe situations where success is a possibility, but the odds are against it. By using these synonyms, one can effectively communicate the idea of taking a chance on something that may or may not succeed.