Amnon in the Bible Encyclopedia - ISBE

am'-non ('amnon, "faithful"; compare 'aminon, 2 Sam 13:20, which is probably a diminutive. Wellhausen (IJG, II, 24, note 2) resolves 'amiynown into 'immi, and nun, "my mother is the serpent"; compare NUN): (1) The eldest son of David and Ahinoam, the Jezreelites (compare 2 Sam 3:2). As the crown prince and heir presumptive to the throne, he was intensely hated by Absalom, who was, therefore, doubly eager to revenge the outrage committed by Amnon upon his sister Tamar (2 Sam 3:2; 13:1 ff, 1 Ch 3:1). (2) A name in the genealogy of Judah (1 Ch 4:20).

Link: https://bible-history.com/isbe/A/AMNON/