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Words that start with O

Orange orangutans avidly ogle an orchard of oleanders in Oregon.

Browse words in categories starting with O

Adjectives (27)

Showing 1-20 of 99

Photo of an oak tree

Ois forOak (Tree)

Oaks are a group of trees and shrubs from the Northern hemisphere. There are both deciduous and evergreen oaks. Most people are familiar with the common oak trees that grow acorns.
Oak wood is used for making furniture, and was once used for making houses. It is still used for making wine barrels.

Brenden Ashton / CC BY-SA

Photo of an oak floor

Ois forOak (Wood)

Oak is timber from the oak tree. It can be used to make floors and furniture.

Sean Gillies / CC BY-SA

Photo of people padding with oars

Ois forOar

An oar, sometimes called a paddle, is a long, thin pole with a wide, flat part at one or both ends. It is used to make a small boat like a canoe move forward, and to help in steering it.

Tirstrup Idrætsefterskole / CC BY-SA

Photo of a bowl of porridge

Ois forOatmeal

Oatmeal is a porridge made from oats, or a word for ground-up oats that you can use in cooking.

Antti T. Nissinen / CC BY-SA

Photo of oats

Ois forOats

Oats are a cereal crop grown mainly for turning into rolled oats and oatmeal for making porridge. It is also used as animal feed, particularly for horses.

David J / CC BY-SA

Photo of an obelisk

Ois forObelisk

An obelisk is a 3 dimensional shape with four sides, tapering towards the top. Obelisks are usually tipped with a pyramid. They are a popular shape for monuments.

Richie Diesterheft / CC BY-SA

Photo of an unfit woman

Ois forObese

You are obese if you are very fat or overweight. Obese people often have health problems because of their size.

Tony Alter / CC BY-SA

Photo of a dog at obedience classes

Ois forObey

You obey when you do what you are told to do. The dog in the picture is at obedience classes.
The opposite of obey is disobey.

Maja Dumat / CC BY-SA

Photo of someone playing the oboe

Ois forOboe

Oboes are a double reed musical instrument in the woodwind family. Oboes have a very clear sound, and can be heard over other instruments. They have a conical hole through their centre, unlike the flute which has a cylindrical one.

Kercia Evelyn Silva Santos / Public Domain

Photo of a lampost obscured by a frosty window

Ois forObscure

Something is obscure if it is unclear or uncertain. Something obscured cannot easily be seen or understood.

The lamp post in the picture is obscured from view.

jenny downing / CC BY-SA

Photo of an observatory

Ois forObservatory

List of structures

An observatory is a building that is made as a place to watch the stars and planets. Observatories are dome-shaped and are usually built on top of high mountains so there is less air between them and space.

Naotake Murayama / CC BY-SA

Photo of a fragment of obsidian

Ois forObsidian

Gems & minerals

Obsidian is a dark glass formed in the larval flows of volcanos. Obsidian doesn't have a crystalline structure and can be broken into very thin pieces that can be used to make a very sharp cutting edge, spear tip or arrow head.

John Atherton / CC BY-SA

Photo of men going through an obstacle course

Ois forObstacle

An obstacle is something that gets in your way when you are trying to do something or go somewhere.

DVIDS / Public Domain

Photo of the roofline of a wooden building.

Ois forObtuse

An obtuse angle is one that is larger than 90 degrees. A 90 degree angle is a "normal" corner, like you find inside most houses and the corners of a piece of paper. An angle smaller than 90 degrees is called acute.

Dan Brady / CC BY-SA

Photo of the ocean

Ois forOcean

The ocean is the vast expanse of salty water that covers most of the Earth.
Another word for ocean is sea.

DVIDS / Public Domain

Photo of Oceania

Ois forOceania

Oceania is a part of the world made up of many islands and countries in the Pacific Ocean. It includes places like Australia, New Zealand, and many Pacific island nations.

New Zealand did not quite fit in the picture, but you can click through to the link below to see the whole series of images from NASA.

NASA / Public Domain

Photo of an ocelot

Ois forOcelot

Feline, Spotted

The ocelot is a wild cat found in South & Central America and Mexico. They look similar to an ordinary cat but have markings on their coat like a jaguar. They live mainly in forested areas and hunt small animals.

Eric Kilby / CC BY-SA

Photo of a stop sign.

Ois forOctagon

An octagon is a shape with eight sides. The stop sign in the picture is an octagon, and it is mostly red.

greg westfall / CC BY-SA

Photo of a calendar that says October

Ois forOctober

October is the tenth month of the year. It has 31 days. The next month of the year is November. In the northern hemisphere October is part of autumn, and in the southern hemisphere it is part of spring.

plenty.r. / CC BY-SA

Photo of an octopus

Ois forOctopus

An octopus is a creature with eight arms that lives in the sea. The bottom of their arms is covered in suction cups. Most octopi have no bones, so they can squeeze into very small holes to hide. Octopi have three hearts and blue blood. Octopi are distantly related to snails.

Mrs. Gemstone / CC BY-SA