The condition of being free from disease or pain is basically what health is. Health refers to a general well being. It is only when someone has a problem with their body, an illness or a disease, that its absence is felt. The World Health Organization(W.H.O.)defines it as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmiity". However, it must be recognized that depending on what country a person lives in and culture a person is part of, health standards will be different. It may be difficult in one country to obtain enough food, clothing, clean water and medical supplies to be healthy according to the definition by W.H.O.
Well, your request was to create a definition about what health is, so I will happily oblige.
For me, health is the state of being healthy physically, mentally, emotionally, socially, spiritually and sexually, and being able to cope with the demands of living everyday. As long as a person can meet his or her needs and they are satisfied holistically, they achieve the state of being healthy holistically and thus are considered to be healthy individuals.
My explanation is that some people, while not overly healthy physically, are able to cope and still satisfy themselves and their lives, and thus should be considered as healthy.
I hope this helps.