noun a dropping tube.
2. dropper ·noun a branch vein which drops off from, or leaves, the main lode.
3. dropper ·noun one who, or that which, drops. specif.: (fishing) a fly that drops from the leaden above the bob or end fly.
4. dropper ·noun a dog which suddenly drops upon the ground when it sights game, formerly a common, and still an occasional, habit of the setter.