Liq`ue*fac"tion (?), n. [L. liquefactio: cf. F. liqu'efaction. See Liquefy.]

1.

The act or operation of making or becoming liquid; especially, the conversion of a solid into a liquid by the sole agency of heat.

2.

The state of being liquid.

3. Chem. Physics

The act, process, or method, of reducing a gas or vapor to a liquid by cold or pressure; as, the liquefaction of oxygen or hydrogen.

© Webster 1913.