| Idiom | Meaning | Example | 
| on the brink | 
close, almost there, on the verge
 | 
Their marriage is failing. They're on the brink of divorce.
 | 
| on the bubble | 
between the ones that pass and fail, may be included or excluded
 | 
There are seven applicants. Two will be interviewed, three will not,
and two are on the bubble.
 | 
| on the button | 
correct, accurate, dead on, spot on
 | 
When Fern guessed my age, she was right on the button: 39.
 | 
| on the carpet | 
asked to explain a mistake, give me the third degree
 | 
Tom's on the carpet because he lost company documents.
 | 
| on the clock | 
o'clock, at the time showing on the clock
 | 
"Did you come to work on time, Michael?"
"Yes, sir. At eight on the clock, sir."
 | 
| on the cutting edge | 
(See the cutting edge)
 | 
 | 
| on the dot | 
exactly on time, not early or late
 | 
The concert started at 7:30 on the dot.
 | 
| on the double | 
quickly, now, move it
 | 
Coach Keyser said, "Sutton, get over here - on the double!"
 | 
| on the edge of your seat | 
very interested in a movie, feeling suspense in a story
 | 
The movie The Firm will have you on the edge of your seat.
 | 
| on the fence | 
(See sit the fence)
 | 
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