| In bygone times | 15 |
| In cahoots | 10 |
| In cahoots w/Warner or Elektra at various points | 48 |
| In cahoots w/Warner or Elektra, one time or another | 51 |
| In Canada, e.g. | 15 |
| In captivity | 12 |
| In captivity, in a way | 22 |
| In cards, an extra hand | 23 |
| In cartoons, a whistle may follow it | 36 |
| In case | 7 |
| In case it happens differently | 30 |
| In case it's called for | 27 |
| In case it's true | 21 |
| In case that | 12 |
| In case that's true | 23 |
| In certain areas it's called Radio Nord Québec | 53 |
| In certain nightwear | 20 |
| In chains | 9 |
| In chaotic disorder | 19 |
| In charge | 9 |
| In charge at home | 17 |
| In charge of | 12 |
| In charge of genealogy? | 23 |
| In charge, as in a family | 25 |
| In check | 8 |
| In cipher | 9 |
| In ciphertext | 13 |
| In circulation | 14 |
| In circulation, as a newspaper | 30 |
| In class | 8 |
| In class, they can be taken or taken away | 41 |
| In Cleveland, I am on dusty infield (7) | 39 |
| In clogs, perhaps | 17 |
| In close combat | 15 |
| In close competition | 20 |
| In close order | 14 |
| In close proximity | 18 |
| In close pursuit | 16 |
| In closest proximity | 20 |
| In clover | 9 |
| In coarse fashion | 17 |
| In coastal Maine | 16 |
| In code | 7 |
| In code, perhaps | 16 |
| In coils | 8 |
| In color | 8 |
| In combat | 9 |
| In comics, it's represented by a string of Z's | 54 |
| In command | 10 |
| In command of | 13 |
| In company | 10 |
| In company (with) | 17 |
| In company with | 15 |
| In comparable shape | 19 |
| In comparison (to) | 18 |
| In comparison with | 18 |
| In competition | 14 |
| In complete disorder | 20 |
| In compliance | 13 |
| In computer science, a characterization of every possible solution to a problem | 79 |
| In concealment | 14 |
| In concert | 10 |
| In conclusion | 13 |
| In conclusion, in Cannes | 24 |
| In conclusion: Fr. | 18 |
| In concord | 10 |
| In concord (with) | 17 |
| In concurrence | 14 |
| In condensed form | 17 |
| In condensed format | 19 |
| In conference | 13 |
| In conflict | 11 |
| In conflict with | 16 |
| In conflict with, with "of" | 37 |
| In conformity with | 18 |
| In confrontation | 16 |
| In confused haste | 17 |
| In confusion | 12 |
| In conjunction | 14 |
| In connection with | 18 |
| In consecutive order | 20 |
| In consequence of which | 23 |
| In constant motion | 18 |
| In contact with | 15 |
| In contempt of | 14 |
| In contention | 13 |
| In contradiction to, with “with” | 40 |
| In contrast to | 14 |
| In control | 10 |
| In control, again | 17 |
| In control, in a way | 20 |
| In copious amounts | 18 |
| In cornrows | 11 |
| In costume | 10 |
| In Cousteau's realm | 23 |
| In crowd | 8 |
| In crude style | 14 |
| In crystal form, it's rock candy | 36 |
| In cubbyholes | 13 |
| In current times | 16 |