The primary Greek word for “confess” is homologeo which basically means “to say the same thing” and then “agree, admit, acknowledge.” The context must determine the precise nature, emphasis, and meaning of the word. Thus, it can mean to acknowledge sin or to confess or acknowledge someone as something. A similar and somewhat more emphatic word is exomologeo, “promise, consent, admit, confess or acknowledge” and from this, “to praise.”

In Psalm 32:5, the word for confess or acknowledge is yada’, which basically means “to know” or in the hiphil stem, “to make known” as in this context. Another word that looks similar, but is different is yadah, “to give thanks, praise,” and then, “to confess” as in Lev. 5:5 where it is used in the hitpael stem giving it the idea of “confess.” See also 2 Chron. 6:26 where it is used in the sense of “confess God’s name.” Another word is nadad, “to be conspicuous,” but in the hiphil stem it means “to make known, declare, tell.”