To blend or mix together smoothly so the parts become unified; in card games, to lay down combinations of cards.
Possibly from Old English 'meltan' (to melt) blended with 'weld,' creating a word that means to merge. The card game meaning emerged in the 1900s.
In cooking, when flavors 'meld' together overnight in a marinade, the chemistry is literally happening—acids and oils are breaking down proteins and carrying flavors deeper.
Complete word intelligence in one call. Free tier — 50 lookups/day.