to disappear.

The polls show him with a big lead now, but his support could melt away before the election.

Usage notes: sometimes used in the form melt something away:

She put on some music that's meant to melt your tension away.

Etymology: from the literal meaning of melt (= to change or cause something to change from solid to liquid)

• a white knight
• a white lie
• a whizz-kid
• a whole new ballgame
• a whole new ball game
• a wide boy
• a wild card
• a wild-goose chase
• a wise guy
• a wish list
• a witch-hunt
• a wolf in sheep's clothing
• a wolf whistle
• a woman after own heart
• a woman after your own heart
• a woman of means
• a woman of the world
• a word to the wise.
• a word to the wise is sufficient.
• a world of difference
• a worm's eye view
• a yes man
• a zero-sum game
• babe in the woods
• baby blues