Cast off or adrift; nautical term meaning to have been set loose from moorings or thrown aside.
From a- (on, in) + cast (to throw). Common in nautical English where 'a-' prefix verbs describe ships or actions in progress.
In old sailing terminology, saying a ship is 'acast' was a way to describe its predicament in a single word—it combined the state and the problem into one quick shout that sailors could understand instantly.
Complete word intelligence in one call. Free tier — 50 lookups/day.