| on purpose |
not by accident; deliberately. |
| on tap |
ready to be served from a cask. [2 definitions] |
| on the air |
broadcast on radio or television. |
| on the average |
usually; generally. |
| on the ball |
acting in a quick and able way. [2 definitions] |
| on the blink |
broken; needing repair. |
| on the contrary |
not agreeing with something already said. |
| on the dot |
(informal) exactly on time; punctually. |
| on the double |
(informal) right away; immediately. |
| on the house |
free, as a gift from a business. |
| 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] |
| on top of |
in total control of. [3 definitions] |
| pat on the back2 |
(informal) to show praise or thanks by words or actions. |