σύμφημιsýmphēmi

to consent, confess: with dative, followed by ὅτι, Romans 7:16.

Greek (New Testament) · G4852

Same root

σύνsýn · G4862with or together (but much closer than G3326 (μετά) or G3844 (παρά)), i.e. by association, companionship, process, resemblance, possession, instrumentality, addition, etc.
φημίphēmí · G5346to show or make known one's thoughts, i.e. speak or say

Where it appears

Appears 1 times in the Bible.

Romans 7:16 But if I know that what I am doing is wrong, this shows that I agree that the law is good.

Source: G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), public domain.