Found just twice in the New Testament (Rom. 13:9Rom. 13:9
English: American Standard Version (1901) - ASV
9 For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not covet, and if there be any other commandment, it is summed up in this word, namely, Thou shalt love thy neighbor as thyself.

WP-Bible plugin; Eph. 1:10Eph. 1:10
English: American Standard Version (1901) - ASV
10 unto a dispensation of the fulness of the times, to sum up all things in Christ, the things in the heavens, and the things upon the earth; in him, I say,

WP-Bible plugin), the Greek verb “anakephalaioo” meant “gather together,” “unite,” or “bring together.”

In Rom. 13:9Rom. 13:9
English: American Standard Version (1901) - ASV
9 For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not covet, and if there be any other commandment, it is summed up in this word, namely, Thou shalt love thy neighbor as thyself.

WP-Bible plugin Paul used this word to “bring together” (summarize) the Old Testament law.  In Eph. 1:10Eph. 1:10
English: American Standard Version (1901) - ASV
10 unto a dispensation of the fulness of the times, to sum up all things in Christ, the things in the heavens, and the things upon the earth; in him, I say,

WP-Bible plugin this verb is used to say Jesus “brings together” (unites) the things on the earth as well as the things in heaven.