1. the light, fluffy seeds of a thistle plant that are carried by the wind

Examples

• The thistledown drifted lazily across the meadow on the summer breeze.
• Children often blow thistledown to watch it float through the air.
• The field was covered with purple thistle flowers that would soon release their thistledown.
• She collected the silky thistledown to use in her nature craft project.
• The wind scattered thistledown far and wide, helping the plants spread to new areas.
• Thistledown is so light that even the gentlest breeze can carry it for miles.