IC l - indi
- in lieu of
- in light of
- in line
- in living memory
- in loco parentis
- in love
- in love with
- in medias res
- in memoriam
- in moderation
- in my opinion
- in no time
- in no uncertain terms
- in no way, shape, or form
- in nubibus
- in office
- in on
- in one hell of a hurry
- in one sitting
- in one's armour
- in one's book
- in one's cups
- in one's element
- in one's eyes
- in one's good books
- in one's midst
- in one's opinion
- in one's own right
- in one's own time
- in one's pocket
- in one's right mind
- in one's sight
- in one's stead
- in one's time
- in one's tracks
- in order
- in order that
- in other words
- in parallel
- in pari materia