An Etymological Dictionary of Astronomy and Astrophysics

(v.int.) To become liquefied by warmth or heat, as ice, snow, butter, or metal. (v.tr.) To reduce to a liquid state by warmth or heat; to fuse.

Etymology (EN): M.E. melten, O.E. meltan “become liquid;”
cf. O.N. melta “to digest;” Gk. meldein “to melt,” L. mollis “soft, mild.”

Etymology (PE): Godâxtan, godâz- “to melt,” from Mid.Pers. vitâxtan, vitâcitan “to melt,” from Av. vi-taxti- “flowing away, melting,” from vi- “apart, away from, out” (O.Pers. viy- “apart, away;” cf. Skt. vi- “apart, asunder, away, out;” L. vitare “to avoid, turn aside”) + tak- “to run, to flow,” taciāp- “flowing water,” tacinti (3pl.pers.act.) “to flow,”
tacar- “course,” tacan “current, streaming;” Mod.Pers. tâz-, tâxtan “to run; to hasten; to assault,” tâzi “swift (greyhound),” tak “running, rush;”
Mid.Pers. tâz-, tâxtan “to flow, to cause to walk,” tc- “to flow, to walk,” tag “running, attack,” tâzig “swift, fast;”
Khotanese ttajs- “to flow, to walk;” cf. Skt. tak- “to rush, to hurry,” takti “runs;” O.Ir. tech- “to flow;” Lith. teketi “to walk, to flow;” O.C.S. tešti “to walk, to hurry;” Tokharian B cake “river;” PIE base *tek^w- “to run; to flow.”