The antonyms for the word "most mothballed" are words that convey the opposite meaning of the phrase. Instead of being unused and abandoned, these antonyms suggest activity and regular use. Some such antonyms include 'active', 'functional', 'working', 'operating', 'vibrant', 'alive', 'flourishing', 'thriving', and 'productive'. While the term 'most mothballed' implies a state of inactivity or disuse, its antonyms signify a thriving and prosperous state of affairs. Using these opposing words can illustrate a contrasting image, which can help convey different emotions and ideas to the reader.