Words that start with O

Olives are the fruit of a small, slow-growing tree. They are originally from the Mediterranean region and grow best in poor soils in Mediterranean climates. Olives can be grown easily from both seeds and cuttings, but trees grown from seed don't always grow good fruit.
Olives can't be eaten fresh from the tree, they are too bitter. Olives need to be prepared by soaking them in salty water or otherwise preparing them to be eaten. Some types of olive can be pressed and oil made from them.

lan An omelette is made from beaten eggs, cooked in a frying pan. A little milk or cream is often added to the eggs, and sometimes omelettes are made from only the white of the eggs, without the yolk.
Omelettes may also contain added herbs, spices, diced vegetables or meat, particularly ham.

extension Something is on if it is powered up and able to be used. The switch in the picture is turned on. On is also used to indicate positioning, as in "the cup is on the table".
The opposite of on is off.

Onions are a vegetable. There are many different kinds of onions, ranging in size and colour from purple to red to white to green.
Onions are used in almost every kind of food, raw or cooked. They can be very sharp when they are raw and many children do not like raw onions, but when they are cooked they are quite sweet.

Oolong is a type of tea made from the leaves of the tea plant, rolled into small balls or twisted into strips. The leaves are partly oxidized, which gives the tea a taste between green tea and black tea.

Opal is not a true mineral, but a crystalline gel made up of spheres of silicon dioxide and water. The pattern of the spheres makes opal refract light into lots of different colours, with blue and green being the most common. Opal is used often in jewelry, and is the national stone of Australia.

extension Something is open if you can go through it or into it. The door in the picture is open. The opposite of open is closed.

lan Opossums are a small to medium sized, common creature that has spread from the western United States. They have a varied diet and are successful breeders. They are the only marsupial found outside of the Australian area.

Or is a word that is used to connect two other words or phrases that are alternatives, for example "do you want beef or chicken?"

Orangutans are reddish-brown apes that live in trees, and are the largest animal that lives entirely in trees. They can weigh up to 113kg, but are usually around 33-82kg. Their arms are twice as long as their legs. Orangutans live almost entirely on fruit, but will also eat leaves, honey and eggs.