| On the blue | 11 |
| On the blue side | 16 |
| On the Board | 12 |
| On the boat | 11 |
| On the border of | 16 |
| On The Border restaurant offering | 33 |
| On the bounding main | 20 |
| On the bride's mind | 23 |
| On the bright side | 18 |
| On the brink | 12 |
| On the brink of | 15 |
| On the briny | 12 |
| On the bulletin board | 21 |
| On the bus | 10 |
| On the button | 13 |
| On the calm side | 16 |
| On the calm side, at sea | 24 |
| On the calmer side | 18 |
| On the calmer side of the boat | 30 |
| On the calmer side of the ship | 30 |
| On the calmer side, at sea | 26 |
| On the calmer side, nautically | 30 |
| On the canvas | 13 |
| On the canvas for good | 22 |
| On the canvas, informally | 25 |
| On the Caribbean | 16 |
| On the Caribbean, e.g. | 22 |
| On the Caribbean, poetically | 28 |
| On the carpet | 13 |
| On the Caspian | 14 |
| On the Celebes | 14 |
| On the Channel | 14 |
| On the cheap end | 16 |
| On the chilly side | 18 |
| On the China | 12 |
| On the clammy side | 18 |
| On the clergyman's mind | 27 |
| On the clock | 12 |
| On the clock? | 13 |
| On the clothesline | 18 |
| On the Coast, maybe | 19 |
| On the con side | 15 |
| On the condition that | 21 |
| On the Constitution | 19 |
| On the Continent | 16 |
| On the contrary | 15 |
| On the cool side | 16 |
| On the Coral | 12 |
| On the couch | 12 |
| On the court's roster | 25 |
| On the crest | 12 |
| On the crest of | 15 |
| On the crown | 12 |
| On the dark side | 16 |
| On the Dead or the Red | 22 |
| On the deck, perhaps | 20 |
| On the decline | 14 |
| On the decline? | 15 |
| On the deep | 11 |
| On the defensive | 16 |
| On the disabled list | 20 |
| On the DL, perhaps | 18 |
| On the docket | 13 |
| On the dot | 10 |
| On the double | 13 |
| On the double! | 14 |
| On the double, briefly | 22 |
| On the double, in memos | 23 |
| On the double, in the O.R. | 26 |
| On the double, in the OR | 24 |
| On the double, initially | 24 |
| On the double, poetically | 25 |
| On the double, when doubled | 27 |
| On the double: abbr. | 20 |
| On the down side | 16 |
| On the down-low | 15 |
| On the downslide | 16 |
| On the dull side | 16 |
| On the edge of one's seat | 29 |
| On the father-of-the-bride's mind | 37 |
| On the FBI's list | 21 |
| On the fence | 12 |
| On the ferry | 12 |
| On the first train out of here, perhaps | 39 |
| On the floor above | 18 |
| On the floor by accident, maybe | 31 |
| On the foul line, ironically | 28 |
| On the fringe | 13 |
| On the fringes | 14 |
| On the fringes, in a way | 24 |
| On the fritz | 12 |
| On the front | 12 |
| On the front burner | 19 |
| On the front line | 17 |
| On the glacial side | 19 |
| On the gloomy side | 18 |
| On the go | 9 |
| On the good side of | 19 |
| On the green | 12 |
| On the groom's mind | 23 |