Webster's Revised Unabridged Dictionary · 1913

At one

At one ({not transcribed})

[Old English at on, atone, atoon, attone.]

1.
In concord or friendship; in agreement (with each other); as, to be, bring, make, or set, at one, that is, to be or bring in or to a state of agreement or reconciliation.
If gentil men, or othere of hir contree Were wrothe, she wolde bringen hem atoon. — Chaucer
2.
Of the same opinion; agreed; as, on these points we are at one.
3.
Together. [Obsolete] — Spenser