From a compound of the base of homou and logos; to assent, i.e. Covenant, acknowledge -- con- (pro-)fess, confession is made, give thanks, promise.
see GREEK homou
see GREEK logos
1. properly, to say the same thing as another, i. e. to agree with, assent, both absolutely and with a dative of the person; often so in Greek writings from Herodotus down; hence,
2. universally, to concede; i. e.
a. not to refuse, i. e. to promise: τίνι τήν ἐπαγγελίαν, Acts 7:17 L T Tr WH (here R. V. vouchsafe); followed by an object. infinitive, Matthew 14:7 (Plato, Demosthenes, Plutarch, others).
b. not to deny, i. e. to confess; declare: joined with οὐκ ἀρνεῖσθαι, followed by direct discourse with recitative ὅτι, John 1:20; followed by ὅτι, Hebrews 11:13; τίνι τί, ὅτι, Acts 24:14; to confess, i. e. to admit or declare oneself guilty of what one is accused of: τάς ἁμαρτίας, 1 John 1:9 (Sir. 4:26).
3. to profess (the difference between the Latin profiteor (`to declare openly and voluntarily') and confiteor (`to declare fully,' implying the yielding or change of one's conviction; cf.pro fessio fidei, confessio peccatorum) is exhibited in Cicero, pro Sest. 51, 109), i. e. to declare openly, speak out freely (A. V. generally confess; on its construction see Buttmann, § 133, 7): (followed by an infinitive, εἰδέναι Θεόν, Titus 1:16); τίνι (cf. Buttmann, as above; Winer's Grammar, § 31, 1 f.) followed by direct discourse with ὅτι recitative, Matthew 7:23; one is said ὁμολογεῖν that of which he is convinced and which he holds to be true (hence, ὁμολογεῖν is distinguished from πιστεύειν in John 12:42; Romans 10:9f): the passive absolute, with στόματι (dative of instrum.) added, Romans 10:10; τί, Acts 23:8; τινα with a predicate accusative (Buttmann, as above), αὐτόν Χριστόν, John 9:22; κύριον (predicate accusative) λησουν, Romans 10:9 (here WH τό ῤῆμα ... ὅτι κύριος etc., L marginal reading Tr marginal reading simply ὅτι etc.; again with ὅτι in 1 John 4:15); Ἰησοῦν Χριστόν ἐν σαρκί ἐληλυθότα (Tr marginal reading WH marginal reading ἐληλυθεναι), 1 John 4:2 and Rec. also in 3 (see below); ἐρχόμενον ἐν σαρκί, 2 John 1:7 (cf. Buttmann, as above; Winer's Grammar, 346 (324)); τινα, to profess oneself the worshipper of one, 1 John 4:3 (here WH marginal reading λύει, cf. Westcott, Epistles of John, p. 156ff) and G L T Tr WH in 4. According to a usage unknown to Greek writers to praise, celebrate (see ἐξομολογέω, 2; (Buttmann, § 133, 7)): τίνι, Hebrews 13:15. (Compare: ἀνθομολογέω (ἀνθομολογοῦμαι), ἐξομολογέω.)