Incarnation - Incarnation, which literally means enfleshment, refers to the conception, and live birth of a sentient creature (generally human) who is the material manifestation of an entity or force whose original nature is immaterial. (wikipedia)

The concept that God became a man and dwelt among other humans. This was rejected by the Gnostic Christians, the Ebionites and other Jewish Christians, but accepted by Pauline Christians. (religious tolerance)

"In the flesh," that is, Christ has come in the flesh, as a genuine human being (John 1:1,14; Romans 8:3; I Timothy 3:16; I John 4:2). This term also indicates that he did not begin to exist at his birth, for John 1:1 states his eternal pre-existence. He was the only one who existed before being born into this world (John 8:58). His coming was historical; it occurred in space-time, on the earth (Matthew 1:18-25; Galatians 4:4) (Answering Islam)