The word "un-fettered" refers to something that is free, unrestrained, or unburdened. Antonyms are words that have the opposite meaning, and in this case, the antonyms for un-fettered include words like restricted, limited, constricted, restrained, or hindered. These words imply that something is being held back, hindered, or prevented from reaching its full potential. When something is unfettered, it is allowed to grow and develop without any interference. However, when something is restricted or limited, it is being held down or held back from its natural path. Therefore, by using antonyms for un-fettered, one can indicate the opposite of freedom or liberation.