While "shoo in" refers to a sure thing or a guaranteed winner, its antonyms are words that denote uncertainty, such as long shot, uncertainty, and underdog. A long shot is a gamble or a risk, as the likelihood of success is very low. Uncertainty implies doubt or unpredictability, indicating that the outcome is unsure. An underdog is a competitor that is perceived to be at a disadvantage, making them an unlikely winner. All three words oppose the idea of a guaranteed outcome associated with being a "shoo in," suggesting that victory is not absolute, and the result is up in the air.