The antonym for the word "most quailing" can vary depending on the context of its usage. Quail is a term that is often associated with fear or apprehension, so the opposite would be a state of confidence, courage, or bravery. Therefore, antonyms for "most quailing" can include terms such as bold, brave, fearless, or intrepid. If the term "quail" is used in the sense of retreating or shrinking back, antonyms can be advance, stand, or move forward. Antonyms for any word should be used wisely as they can significantly change the meaning of a sentence or statement.