Dram (noun)

1. A unit of weight equal to 1/16 ounce (1.77 grams) or 1/8 fluid ounce (3.55 milliliters) in the apothecaries' system.
2. A small quantity of a liquid, especially an alcoholic drink.

Origin:

Middle english: from old english drān "a drink", of germanic origin; related to dutch dronk "drink" and german trank "drink".

Examples:

1. The medicine was dispensed in drams.
2. He poured a dram of whiskey in his coffee.
3. The recipe called for a dram of vanilla extract.
4. The dram of medicine was measured in a graduated cylinder.
5. He took a dram of the tonic to help him sleep.