What Does Cast Off Mean?

To Cast Off Meaning

Definition: To unfasten something or set something free, usually a ship.       

Origin of Cast Off

This phrasal verb became popular in the 1700s. It is unclear exactly how it came into use.

However, cast comes from the Old Norse word kasta. It can mean to throw. One of the definitions of cast off is to set a boat free from its moorings. It probably became popular as maritime activities became more and more widespread in the industrialized world.

Over time, people began to use the expression to describe releasing things other than just ships.

Examples of Cast Off

Castoff definitionIn the example below, two siblings are discussing a family boating excursion.

Jordan: Can you hurry up? The rest of the family already has their boats in the middle of the lake.

James: I know, but I can’t figure out how to work this sail. Why don’t you help me to cast off from the dock?

Jordan: I would, but I’m scared of the water. I don’t want to lean over the side to untie the rope.

James: Fine, I’ll do it. But you’ll have to help with something else.

Define casting offIn the second dialogue, one coworker is complaining to another about his son’s suspension from school.

Herman: I just got a call from my son’s school. Apparently, he is being suspended.

Alison: That’s awful. What did he do?

Herman: Nothing that was very bad. I think suspending him is a huge overreaction.

Alison: Maybe you could ask them to reconsider.

Herman: No, I’ll demand that they reconsider. They can’t just cast students off from the school. They have a duty to provide an education for all the citizens of the district.

Cast off has two main uses, as illustrated above. You can cast off from something (dialogue one). This is used with boats and ships. You can also cast something off (dialogue two). This also applies to boats, but it also has a broader use for people, things, etc.

More Examples

This excerpt is about flooding waters being so high that boats are in danger of becoming loose from their docks.

One of the Seine’s tributaries had not seen water levels this high since 1910, when the Great Flood of Paris swamped the capital.

  • Boats and barges docked in Paris were being carefully watched to ensure none would cast off their moorings. –OC Register

The second excerpt is about greyhound racing. Oftentimes, when greyhounds are no longer fast enough to win races, their owners abandon them.

  • Hemopet saves greyhounds, the famous speedsters, from often-brutal racetrack conditions that can leave them lame and cast off when they stop winning; some once were even put to sleep after they stopped winning. Dog racing is legal in seven states, including Florida, Oklahoma and Texas. –OC Register


To cast off from is an expression that usually means to untie a boat so it can leave the dock. Cast off can also mean to reject something or someone.