According to Dictionary.com, "incarnation" means a living being embodying a deity or spirit. The word also means a person or thing regarded as embodying or exhibiting some quality or idea and the assumption of human form or nature.
Theologically, incarnation means the doctrine that the second person of the Trinity assumed human form in the person of Jesus Christ and is completely both God and man. In short, a divine person was united to a human nature to save the world from original sin.
The common English word "incarnation" originates from the Latin word "incarnare," meaning to make or turn into flesh.