ord. Ordained; Order; Ordinary; Ordnance.
Or. Oregon.
O.S. Old Style.
O.S.A., Ordinis Sancti Augustini=Of the Order of St Augustine.
O.S.B., Ordinis Sancti Benedicti=Of the Order of St Benedict.
O.S.F., Ordinis Sancti Francisci=Of the Order of St Francis.
O.T. Old Testament.
Oxf. Oxford.
Oxon., Oxonia=Oxford;—Oxoniensis=Of Oxford.
oz. Ounce.