dropper

noun13

1. •
   One who drops something, especially one who drops a specific item to cause mischief.

   • The dropper left the suitcase with the bomb next to the garbage can.
2. •
   A utensil for dispensing a single drop of liquid at a time.

   • 'Cause when the blood begins to flow When it shoots up the dropper's neck[…] — 1964
3. •
   A software component designed to install malware on a target system.
4. •
   A seat post whose height can be adjusted while riding.
5. •
   (informal) A drop shot.
6. •
   (slang) A person who uses fraudulent cheques.

   • […] 'dropper' — the person who presents the cheque at the bank or elsewhere — who takes the risk. […] On the other hand, 'kite droppers' usually work in teams. — 1973
7. •
   The young bulb of a tulip, not of flowering size.
8. •
   (Australia) A batten fixed to a post-and-wire fence to keep the wires apart.
9. •
   A fly that drops from the leaden above the bob or end fly.
10. •
    A dog which suddenly drops upon the ground when it sights game.
11. •
    A branch vein which drops off from, or leaves, the main lode.
12. •
    (historical) A delivery by lob bowling (no longer legal).
13. •
    (historical) A bowler who makes such deliveries.