The phrase "most trussed" refers to something that is tightly restrained or secured. Synonyms for this phrase include bound, tied up, shackled, fastened, secured, strapped, cinched, and fettered. Each of these words implies a sense of being tightly held or restricted in movement. "Bound" suggests being tied with ropes or other bindings, while "shackled" implies being held in chains or handcuffs. "Fastened" could refer to anything from a seatbelt to a tightly buckled shoe. "Secured" and "fettered" might refer to something that is confined or imprisoned. Overall, these synonyms convey a sense of being restricted, immobilized, or limited in movement.