| opossum |
any of a number of American marsupials that are active at night and live in trees. [2 definitions] |
| opponent |
one who opposes; antagonist; foe. |
| opportunity |
a chance that makes something possible or that may bring about some benefit. [2 definitions] |
| oppose |
to think, act, or be against; resist or obstruct. [3 definitions] |
| opposed |
not in favor of; against. |
| opposite |
located at or on the sides opposing each other; facing. [7 definitions] |
| opposition |
the act or state of opposing, or the state of being opposed. [3 definitions] |
| oppress |
to treat harshly, brutally, or unfairly. [2 definitions] |
| opt |
to decide; choose (usu. fol. by "for" or an infinitive). |
| optical |
of or concerning the sense of sight or the eye. [5 definitions] |
| optician |
a person who sells or manufactures eyeglasses, contact lenses, or other optical devices. . |
| optimism |
the belief that everything will turn out well, or that there are good aspects of every situation. (Cf. pessimism.) [3 definitions] |
| optimistic |
expecting or tending to expect favorable outcomes. [2 definitions] |
| option |
the right, power, or freedom to choose. [4 definitions] |
| optional |
not required; left to one's choice. |
| optometrist |
one who practices optometry. |
| -or1 |
a variant of -er1. |
| OR1 |
abbreviation of "Oregon," a northwestern U.S. state on the Pacific coast between Washington and California. |
| OR2 |
abbreviation of "operating room." |
| or |
used to indicate alternatives. [5 definitions] |
| oral |
spoken, as opposed to written; accomplished by speaking. [3 definitions] |