- in low spirits
- in luck
- in manuscript
- In many ways
- in marked contrast to
- in marked contrast with
- inmate
- inmates
- in medieval/ancient/prehistoric times
- in medieval times
- in memoriam
- in memory
- in memory of
- in microcosm
- in midstream
- in mind
- in miniature
- in mint condition
- in mixed company
- in moderation
- in modern memory
- in (modern/recent) memory
- in more ways than one
- inmost
- in mothballs