1. (v. t.) To disperse and cause to disappear\; -- used esp. of the dispersion of things that can never again be collected or restored.
2. (v. t.) To destroy by wasteful extravagance or lavish use; to squander.
3. (v. i.) To separate into parts and disappear; to waste away; to scatter; to disperse; to vanish; as, a fog or cloud gradually dissipates before the rays or heat of the sun; the heat of a body dissipates.
4. (v. i.) To be extravagant, wasteful, or dissolute in the pursuit of pleasure; to engage in dissipation.