Dissipation is the act of breaking up and scattering or spreading widely. With the dissipation of the clouds, you could enjoy the sunny afternoon — if only you didn't have to work.
Dissipation also refers to wasteful or thoughtless spending or activity. Your habit of taking old clothes and appliances to the dump instead of donating them to charities is a kind of dissipation. Dissipation can also mean a life of indulgence, in which health and wealth are squandered in the pursuit of pleasure. Your uncle's life of dissipation, throwing money at wine and women, will ultimately only bring heartache.