A small tube with a vacuum bulb at one end for drawing liquid in a releasing it a drop at a time; SYN. eye dropper.
1. One that drops
2. A short glass tube fitted with a rubber bulb and used to measure liquids by drops — called also eyedropper, medicine dropper

A small tube topped with a rubberized bulb, used for sucking up fluid and expelling it one drop at a time.