| operate |
to work or run. [3 definitions] |
| operation |
the act or process of working or running. [4 definitions] |
| operator |
someone who controls the working of a machine or the activities of a business. [2 definitions] |
| operetta |
a short, funny opera, with words that are spoken as well as sung. |
| ophthalmologist |
a doctor who works in the branch of medicine that studies and treats diseases of the eye. |
| ophthalmology |
the branch of medicine that studies and treats diseases of the eye. |
| opinion |
what one thinks about something or somebody; viewpoint. An opinion is not necessarily based on facts. Feelings and experiences usually help a person form an opinion. [3 definitions] |
| opossum |
a small mammal with gray fur, a pointed nose, and a long tail, which it uses to hang from tree branches. The common opossum is the only marsupial that lives in North America. Several other kinds of opossums live in Central and South America. The female opossum carries her young in a pouch in her belly. [2 definitions] |
| opponent |
one who fights, plays, or takes a position against another. |
| opportunity |
a chance for a better situation. [2 definitions] |
| oppose |
to think, act, or be against; resist. [2 definitions] |
| opposed |
not in favor of; against. |
| opposite |
located at or on the sides across from each other; facing. [4 definitions] |
| opposition |
the act or state of being against, or the state of having someone against another. [3 definitions] |
| oppress |
to treat in a way that is cruel or not fair. [2 definitions] |
| opt |
to decide; choose (usually followed by "for" or an infinitive). |
| optical |
of or having to do with the sense of sight or the eye. [2 definitions] |
| optician |
a person who makes or sells eyeglasses and contact lenses. |
| optimism |
the belief that things will turn out well or that there is always hope for something good to happen. |
| optimistic |
likely to be hopeful that things will work out well. |
| option |
the right, power, or freedom to choose. [2 definitions] |