Epideiknumi combines epi (upon) + deiknumi (to show, point out). It means to show clearly, to demonstrate, or to exhibit — often with the intent to prove or compel recognition. It appears 7 times in the NT.
Jesus uses epideiknumi when He shows Himself alive to the disciples: "He presented himself alive to them after his suffering by many convincing proofs" (Acts 1:3, related word). The Pharisees use it when Jesus asks for a coin: "Whose image is this?" The act of showing is the act of revelation. The incarnation itself is God's epideiknumi — showing us what He is like. "Anyone who has seen me has seen the Father" (John 14:9). The resurrection appearances are God's ultimate demonstration that death does not have the final word.