ἀνακεφαλαιόω (anakepalaióō) is a Greek verb meaning:

1. To Summarise: To recapitulate or bring together the main points of a discussion or argument.
2. To Head Up: To gather or sum up everything under a single head or principle.

In essence, it signifies the action of summarizing or bringing together different elements into a unified whole.

Detailed Overview with Concordances

1. BDAG (A Greek-English Lexicon of the New Testament and Other Early Christian Literature):

• BDAG defines ἀνακεφαλαιόω as “to sum up” or “to recapitulate.” It describes the term as bringing together different elements or parts into a single summary or head. BDAG notes its use in Ephesians 1:10 to denote the act of uniting everything under Christ.

2. LSJ (Liddell-Scott-Jones Greek-English Lexicon):

• LSJ describes ἀνακεφαλαιόω as “to bring together” or “to summarise.” It highlights its use in a legal or rhetorical context where elements or parts are summarized or unified under one head.

3. Thayer’s Greek Lexicon:

• Thayer defines ἀνακεφαλαιόω as “to bring together” or “to recapitulate.” It emphasizes the term’s meaning of gathering various elements into a summary or overall principle, particularly in the context of summarizing an argument or discussion.

4. Strong’s Concordance:

• Strong’s Concordance lists ἀνακεφαλαιόω as G346 and defines it as “to sum up” or “to head up.” It emphasizes the idea of bringing together different parts into a unified whole, as used in Ephesians 1:10 to describe the unification of all things under Christ.

Summary:
ἀνακεφαλαιόω (anakepalaióō) means “to sum up” or “to bring together” in Greek. According to BDAG, LSJ, Thayer’s Greek Lexicon, and Strong’s Concordance, the term involves summarizing or uniting various elements into a coherent whole. It is used in Ephesians 1:10 to denote the act of unifying all things under Christ, reflecting its role in bringing together disparate parts into a unified summary or principle.