Authors:

I use the term happiness to refer to the experience of joy, contentment, or positive well-being, combined with a sense that one's life is good, meaningful, and worthwhile.

Sonja Lyubomirsky (2007). “The How of Happiness: A New Approach to Getting the Life You Want”, p.37, Penguin
I use the term happiness to refer to the experience of joy, contentment, or positive well-being, combined with a sense that one's life is good, meaningful, and worthwhile.