n. The act of resolving or the state of being resolved into vapor; the conversion of a solid or liquid by heat into vapor, fumes, or steam; vaporization.n. The matter evaporated or exhaled; vapor.n. In algebra, the disappearance of a solution of a system of equations by passing off to infinity. Thus, the solution of the two equations x—ky = a and x—y = b, which disappears when k = 1, is said to pass off by evaporation.