Definition:
happiness is a state of being or a feeling associated with contentment, satisfaction, joy, and inner peace. It is the result of receiving something we want, being with someone we love, and/or accomplishing a goal we strive for. It can also manifest itself due to an overall sense of satisfaction in life or in our environment. When happiness is used as a noun, it is usually an uncountable mass noun.
Examples:
1. Harry felt a sense of happiness overwhelm him as he admired the breathtaking sights of the Grand Canyon.
2. Jenny found happiness in spending quality time with her family hearing their adventures over dinner.
3. His material items may have brought him temporary happiness, but the lasting pleasure of giving to charity made him much more content.
Tips:
when using happiness as a noun, context may be necessary to explain which kind of happiness is being expressed.