A restriction that forbids a quantity from rising above a given or current level: a freeze on city jobs; a proposed freeze on the production of nuclear weapons.
Most liquids freeze by crystallization, formation of crystalline solid from the uniform liquid. This is a first-order thermodynamic phase transition, which means that as long as solid and liquid coexist, the temperature of the whole system remains very nearly equal to the melting point due to the slow removal of heat when in contact with air, which is a poor heat conductor. [citation needed ...