When someone is really cheerful and sunny and happy all the time, this person might be described as the embodiment of happiness.
- an embodying or being embodied
- that in which something is embodied; concrete expression of some idea, quality, etc.: she is the embodiment of virtue
- The act of embodying or the state of being embodied.
- One that embodies: “The flag is the embodiment, not of sentiment, but of history” ( Woodrow Wilson )
From embody + -ment.