a·jar / əˈjär/ • adv. & adj. (of a door or other opening) slightly open: [as adv.] she had left the window ajar that morning | [as adj.] the door to the sitting room was ajar. a·jar² • adv. archaic out of harmony.

ajar slightly open. XVIII. alt. of Sc. and north. dial. achar, on char(e) (XVI), i.e. ON, A-1, and char :- OE. ċerr (WS. ċierr) turn (see CHARE). The earliest records of the j-form (XVII) are in the analytical var. at jar, (up)on the jar, etc.