| Vocabulary Words | Meanings |
|---|---|
| opening | an open place; a hole or space |
| operate | to act, work, produce effect, drive, as a machine |
| operation | something that is done, especially something done by doctors in hospital to make people well again |
| opinion | what you think about something |
| opportune | seasonable, timely, convenient |
| opportunist | a politician of changing nature, according to the call of selfish need |
| opportunity | a chance to do something |
| oppsite | as different as possible from something else; across from |
| optical | having to do with eyes or with seeing |
| orange | a sweet fruit. The same word also means the colour of the fruit |
| orbit | the path in which something moves around another thing in space |
| orchard | a lot of fruit trees growing together |
| order | a command. The same word also means to ask for something to be done; such as for something to be sent to you from a shop |
| ordinary | usual; not special or different |
| ore | rock or mineral from which we get metal |
| organ | a large musical instrument with a keyboard and pipes that the sounds come from; part of the body, army or country |
| organization | a group of people or of nations who get together to work for a particular purpose; such as the World Health Organization |
| organize | to get a group of people together for a particular purpose: to plan and arrange something |
| ornament | anything used to make something look prettier, such as jewellery or a vase |
| orpanage | a home for orphans, the sate of an orphan |
| orphan | a child whose mother and father are both dead |
| ostrich | a very large bird which has long legs but which can not fly because its wings are too small |
| otherwise | if not; if things are different |
| ought to | in place of should or must when duty or moral obligation is needed |
| ounce | a measurement of weight. There are 16 ounces in a pound |
| outburst | a sudden bursting out, such as cheering when a goal is scored at a football match |
| outfit | a set of clothing or equipment |
| outing | a pleasure trip or walk |
| outlaw | a person who fights against the law and is told that he cannot be protected by the law. Robin Hood and his men were outlaws |
| outline | a line drawn to show the shape of something round the outside edge. The same word also means the main ideas of a story or a plan |
| outside | the opposite of inside; out of doors |
| oval | egg-shapped. A rugby football is oval |
| oven | the inside part of a stove where you bake things a piece of clothing worn over other clothes to keep them clean |
| overall | an outdoor coat worn over all your other clothes |
| overthrow | completely |
| owe | to need to pay for something you |
| owl | a bird with big eyes and a sharp curved beak. Owls fly at night and sleep through the day |
| own | to have something that belongs to you |
| oxen | bulls and cows |
| oyster | a shellfish with a very hard flat shell in two parts |
Examples of back formation
1.Baby-sit (baby-sitter)
2.Gyre (gyroscope)
3.Edit (editor)