dropper
Pronunciation: /ˈdrɒpə/
noun
- 1a short glass tube with a rubber bulb at one end and a tiny hole at the other, for measuring out drops of medicine or other liquids: oils sold in bottles with a rubber-tipped dropper an eye dropper

Origin:
mid 17th century (in the sense 'a person who lets something drop'); dropper (sense 1) is first recorded in the late 19th century