| on the mend |
getting better after an injury. |
| on the off chance |
with the very slight possibility; against the slight hope. |
| on the shelf |
not in use at the present time; put aside until later. |
| on the sly |
secretly; in a crafty way. |
| on the spot |
at once; immediately. [2 definitions] |
| on the spur of the moment |
without much thought. |
| on the whole |
all things considered; in general. |
| on tiptoe |
standing or walking on the toes, especially to proceed quietly or cautiously. [2 definitions] |
| onto |
to a position on or on top of. [2 definitions] |
| on top of |
in total control of. [3 definitions] |
| onward |
toward a point or position ahead in space or time. [2 definitions] |
| ooze1 |
to leak out slowly. Liquids, gases, and sounds may ooze. |
| opal |
a mineral that is white, black, blue, or yellow. Opals are used as gems. |
| opaque |
not letting light pass through. [2 definitions] |
| OPEC |
an association made up of several Arab nations that sell the oil they produce to other countries. "OPEC" is an abbreviation of "Organization of Petroleum Exporting Countries." |
| open |
allowing something or someone to pass through or to get to the inside; not shut or closed. [16 definitions] |
| opener |
someone or something that opens. [3 definitions] |
| opening |
the act, process, or result of making open or causing to become open. [5 definitions] |
| openly |
in a way that involves no hiding or lying. |
| open-minded |
not having made opinions or decisions ahead of time; willing to consider new ideas. |
| opera1 |
a play in which all or most of the words are sung and the music is played by an orchestra. |