This door is ajar.
The definition of ajar refers to something that is slightly opened.
Leaving a shoe in the doorway so that is will not shut is an example of a door being ajar.
slightly open: the door stood ajar
Origin of ajarMiddle English on char, a-char ; from Old English cier, a turn: see chore
not in harmony
Origin of ajara- + jar
Partially opened: left the door ajar.
Origin of ajarMiddle English on char : on, in; see on + char, turn (from Old English cierr).
- A member of an ethnographic group of Georgians.