Source : Webster's Revised Unabridged Dictionary (1913)

Liquefy \Liq"ue*fy\ (-f[imac]), v. t. [imp. & p. p. {Liquefied}
   (-f[imac]d); p. pr. & vb. n. {Liquefying} (-f[imac]`[i^]ng).]
   [F. liqu['e]fier, L. liquere to be liquid + facere, -ficare
   (in comp.), to make. See {Liquid}, and {-fy}.]
   To convert from a solid form to that of a liquid; to melt; to
   dissolve; and technically, to melt by the sole agency of
   heat.

Liquefy \Liq"ue*fy\, v. i.
   To become liquid.

Source : WordNet®

liquefy
     v 1: become liquid; "The garden air overnight liquefied into a
          morning dew"
     2: make (a solid substance) liquid, as by heating; "liquefy the
        silver" [syn: {liquify}, {liquidize}, {liquidise}]
     3: become liquid or fluid  when heated; "the frozen fat
        liquefied" [syn: {flux}, {liquify}]
     [also: {liquefied}]