| oak |
An oak is a kind of tree. It is a strong tree that can grow very big and tall. The wood of an oak is hard, and it is often used to make things like floors and furniture. |
| oar |
An oar is something that people use to make a boat move or turn in the water. It is a long piece of wood or metal that is wide and flat at one end. An oar is often attached to its boat, but it can move too. Boats that use oars usually have two of them. |
| obey |
When you obey someone or something, you do what that person or thing tells you to do. |
| object |
An object is anything that you can see or touch. [2 definitions] |
| oboe |
An oboe is a kind of instrument for making music. Oboes are usually made of wood. An oboe has the shape of a tube, and you blow through it to make a sound. The body of the oboe has holes that the fingers cover or uncover to change the notes. The oboe makes a very special kind of sound because the part of the oboe that goes in your mouth is quite different from what other similar instruments have. |
| occasion |
An occasion is a time of something happening or of someone doing something. If you had an occasion of helping your dad wash the car, it means that you had a time when you did that. If you went to a concert on three occasions, you went to a concert three times. [2 definitions] |
| occur |
When something occurs, it happens. We often use the word occur when we talk about things happening such as earthquakes, floods, accidents, and important events in people's lives. [2 definitions] |
| ocean |
An ocean is one of the very large bodies of salt water on the earth. Oceans are much bigger than any lake or other body of water. Most of our planet is covered by oceans. Altogether, there are five oceans. Our continent, North America, is between the Atlantic Ocean and the Pacific Ocean. The other three oceans are the Indian Ocean, the Arctic Ocean, and the Southern Ocean. |
| Oceania |
Oceania is a group of many islands in the central, western, and southern part of the Pacific Ocean. Some of the islands are Fiji, Tonga, Samoa, and Vanuatu. The island countries of New Zealand and Australia are sometimes considered part of Oceania too. |
| o'clock |
O'clock means "of the clock," and it is a word we use when we are talking about a particular time of the day, especially an exact hour of the day, such as eight in the morning, three in the afternoon, or six in the evening. |
| October |
October is the tenth month of the year. |
| octopus |
An octopus is an animal that lives in the sea. It has a soft body and eight long "arms." These arms help the octopus move through the water and catch food. Octopuses eat crabs, lobsters, and other small sea animals. |
| odd |
When something is odd, it is different from what is expected or usual. It is strange. [2 definitions] |
| odd number |
An odd number is a number that can't be divided exactly by two. Three, five, seven, and nine are some of the odd numbers. |
| of |
We often use of when we are talking about something belonging to or being connected with a person or thing. The name of your family, is your family's name. The sister of your mother is your mother's sister. [8 definitions] |
| off |
When something has come off, it is not attached to some surface anymore. If your bandage has come off, it is not lying against your skin anymore. [7 definitions] |
| offer |
When you offer something to someone, you present it to them and see if they want it or not. If you want to give your dog a treat and you show it to him in your hand, you are offering the treat to him. |
| office |
An office is a place where people work. In an office, there are usually desks, computers, and telephones. [2 definitions] |
| office building |
An office building is a place where many people work. An office building can be used by one business or by many different businesses. In an office building, most people work at desks and computers. |
| officer |
An officer is a person who has an important position in a company or in a government. An officer has some power over other people and a lot of responsibility. The president of a company is that company's top officer. A mayor is the top officer in the government of a city. [2 definitions] |
| often |
When you do something often, you do it a lot. If you go swimming often, maybe you go every day or every week. Also, if someone asks you how often you do something, they want to know how many times you do it. |