| In one's right mind | 23 |
| In one's salad days | 23 |
| In one's second childhood | 29 |
| In one's senses | 19 |
| In one's slip? | 18 |
| In one's solitude | 21 |
| In one's spare time | 23 |
| In one's Sunday best | 24 |
| In one's Sunday finest | 26 |
| In one's tree? | 18 |
| In one's ___ | 16 |
| In one's ___ (drunk) | 24 |
| In one's _____ eye | 22 |
| In oneÂ’s Sunday best | 24 |
| In open court | 13 |
| In open sight | 13 |
| In operation | 12 |
| In opposite order | 17 |
| In opposition | 13 |
| In opposition to | 16 |
| In opposition to one another | 28 |
| In opposition to, with "of" | 37 |
| In opposition, to Keats | 23 |
| In optimum acceleration mode | 28 |
| In optimum conditions | 21 |
| In or out trailer | 17 |
| In orbit | 8 |
| In order | 8 |
| In order (to) | 13 |
| In order that | 13 |
| In order that one might | 23 |
| In order to | 11 |
| In order, perhaps | 17 |
| In orderly formation | 20 |
| In ordinary language | 20 |
| In other days | 13 |
| In other respects | 17 |
| In other ways | 13 |
| In other words | 14 |
| In other words, for Caesar | 26 |
| IN OTHER WORDS, HE'S A FINE FATHER | 38 |
| In other words, in Caesar's words | 37 |
| In other words, in old Rome | 27 |
| In other words, in other words | 30 |
| In other words, in Ovid's words | 35 |
| In other words, it comes in 100 tiny pieces | 43 |
| In other words, it'll break in 24 hours | 43 |
| In other words, mom or dad will be out at midnight searching for an open store | 78 |
| In other words, mom or dad will have to operate it | 50 |
| In other words, no way it'll perform as advertised | 54 |
| In other words, to Brutus | 25 |
| In other words, to Caesar | 25 |
| In other words, to Nero | 23 |
| In other words, you must spend $500 more to please your child | 61 |
| In our ___ (with us) | 20 |
| In overtime | 11 |
| In oxfords, say | 15 |
| In pain | 7 |
| In pairs | 8 |
| In pairs, botanically | 21 |
| In pairs: prefix | 16 |
| In pandemonium | 14 |
| In paradise | 11 |
| In part | 7 |
| In part, it's minor | 23 |
| In particular | 13 |
| In particular: Abbr. | 20 |
| In parts | 8 |
| In party mode | 13 |
| In past centuries | 17 |
| In past time | 12 |
| In payment of | 13 |
| In peace | 8 |
| In peak position? | 17 |
| In pencil, for example | 22 |
| In people? | 10 |
| In perfect alignment | 20 |
| In perfect condition | 20 |
| In perfect focus | 16 |
| In perfect formation | 20 |
| In perfect health | 17 |
| In perfect pitch | 16 |
| In peril | 8 |
| In perpetuity | 13 |
| In perpetuum | 12 |
| In person | 9 |
| In person? | 10 |
| In phone limbo | 14 |
| In phrases, something to share or hit | 37 |
| In pieces | 9 |
| In pieces, perhaps | 18 |
| In pigtails, e.g. | 17 |
| In pitch | 8 |
| In place | 8 |
| In place of | 11 |
| In place of that | 16 |
| In place? | 9 |
| In places | 9 |
| In plain English | 16 |
| In plain sight | 14 |