liq·ue·fy verb alsoliq·ui·fy\ˈlikwə̇ˌfī\ (-ed/-ing/-s) Etymology: Middle French liquefier, modification (influenced by Middle French -fier -fy) of Latin liquefacere — more at liquefacient transitive verb : to reduce to a liquid state — used both of solids and gases intransitive verb : to become liquid