The phrase "casts anchor" refers to the act of dropping an anchor to secure a ship in place. Antonyms for this phrase would include words and phrases that describe the opposite action. Some examples of antonyms for "casts anchor" include "sets sail," "deploys," "pulls up anchor," "hoists sail," and "heads out to sea." These antonyms describe the act of starting a journey or moving away from a current location. In contrast, "casts anchor" implies readiness to stay put or dock at a certain location. Understanding antonyms can be helpful in identifying contrasting ideas and expanding one's vocabulary.