| overwhelm |
If something overwhelms you, it gives you an especially heavy load or burden all at once. It is too much or nearly too much for you to handle. [3 definitions] |
| overwork |
to cause to work too many hours; tire completely with work. [3 definitions] |
| owe |
When you owe someone a dollar, it means that they gave you a dollar sometime before now and you still have to pay them back. [2 definitions] |
| owl |
An owl is a bird that hunts for food at night. Owls have large eyes, strong legs, and sharp claws. |
| own |
When you have your own thing, it means that you have a thing that is yours and not anybody else's. [4 definitions] |
| owner |
An owner is a person who owns something. If a person owns something, it is theirs. |
| ownership |
the state or fact of being an owner. [2 definitions] |
| ox |
An ox is one of a breed of large cattle used on farms to pull heavy loads. When we talk about more than one ox, we call them "oxen." |
| oxbow |
a wooden collar in the shape of a U that goes around the neck of an ox. It is fastened to a yoke. |
| oxen |
"Oxen" is the word we use when we are talking about more than one ox. "Oxen" is the plural form of "ox." |
| oxeye daisy |
a daisy that has a bright yellow center with white petals around it. |
| oxford |
a sturdy, plain shoe that laces over the top of the foot. |
| oxide |
a compound that includes oxygen. |
| oxidize |
to combine with oxygen. [2 definitions] |
| oxygen |
Oxygen is a gas that is a part of air. Oxygen has no color or smell, and we can't see it. When we breathe, our bodies take in oxygen from the air. Without oxygen, we cannot live. Other living things need oxygen too. |
| oyster |
An oyster is a small animal with a soft body and a hard shell that has two parts that can open and close. Oyster shells are very shiny inside, and sometimes pearls grow in them. Oysters live in shallow parts of the ocean. |
| oz. |
abbreviation of "ounce" or "ounces." |
| ozone |
a form of oxygen that occurs when oxygen is exposed to an electrical charge, like lightning. It is found naturally in Earth's atmosphere. |
| ozone hole |
an area in the ozone layer where the ozone becomes thin. There is a large ozone hole over Antarctica and a smaller one over the North Pole. Scientists warn us this is dangerous. |
| ozone layer |
an atmospheric layer between ten and twenty miles above the earth that contains a large amount of ozone, which absorbs certain types of harmful radiation from space. |
| P2 |
symbol of the chemical element phosphorus. |