Lexical Definition

‎ἀνακεφαλαίομαι‎ anakephalaíomai (an-ak-ef-al-ah'-ee-om-ahee) to summarise ^G:V
from ‎ἀνά‎ and ‎κεφαλαιόω‎ (in its original sense)

briefly comprehend, gather together in one.

• to sum up

Abbott-Smith

** ἀνα-κεφαλαιόω, ῶ (v.s. κεφαλαιόω), [in Th., Al.: Ps 71 (72):20**;]
to sum up, gather up, present as a whole: mid., Ro 13:9, Eph 1:10 (on WH. v. Lft., Notes, 321 L; AR, in l.; Cremer, 354, 748).†

Abbott-Smith References

Liddell-Scott-Jones

ἀνακεφαλαιόομαι-όομαι,

sum up the argument, of an orator, [Refs 4th c.BC+]:—passive, to be summed up, ἐν τῷ λόγῳ τούτῳ[NT]

_{LSJ Scripture Refs: Rom.13.9}