20kWEB: Origin of the word Ajar. Etymology of the word Ajar. Etymology Dictionary.

AJAR, on the turn; only used of a door or window. (E.) A corruption of a-char, which again stands for on char, i.e. on the turn; from M.E. char, a turn.

'Quharby the day was dawyn, weil I knew;
A schot-wyndo onschet a litill on char,
Persauyt the morning bla, wan, and bar.'
G. Douglas, tr. of Virgil; Prol. to Book vii.

It means 'I undid a shot-window, a little ajar.' [Jamieson quotes this, and explains it rightly, but wrongly adds another example in which on char means 'in a chariot,' the Latin being bijugis; Æn. x. 399.] The M.E. char was earlier spelt cherre, as in the Ancren Riwle, pp. 36, 408; it is not an uncommon word; see seven examples in Stratmann.—A.S. on cyrre, on the turn; where cyrre is the dat. case of cyrr, a turn, turning, time, period.—A.S. cyrran, cirran, cerran, to turn; Grein, i. 156, 161, 180. + O.H.G. cheren, cherren (G. kehren), to turn.—✔GAR, perhaps in the sense to turn; cf. Gk. γυρός, round, γῦρος, a circle. See Fick, i. 73; who assigns a different sense. [†]

ADDENDA

It is worth adding that the A.S. cyrre (better cerre), dat. of cerr, a turn, usually appears in adverbial phrases. Thus æt sumum cyrre, at some time, Luke xxii. 32; æt óðrum cerre, at another time, Ælfred, tr. of Boethius, cap. xxxv. § 2; æt ánum cierre, at the same time, Ælfred, tr. of Gregory's Past. Care, cap. lxi., ed. Sweet, p. 455, last line.

Etymology Dictionary

Origin of the word AJAR. Etymology of the word AJAR.