This door is ajar.
Leaving a shoe in the doorway so that is will not shut is an example of a door being ajar.
Origin of ajarMiddle English on char, a-char ; from Old English cier, a turn: see chore
Origin of ajara- + jar
Origin of ajarMiddle English on char : on, in; see on + char, turn (from Old English cierr).
- A member of an ethnographic group of Georgians.