The term ONE EIGHTH OF A FLUID OUNCE can be represented by two words: DRACHM (6 letters) and DRAM (4 letters). A drachm is a unit of measurement that is equal to one eighth of a fluid ounce, or 3.55 milliliters. A DRAM is also a unit of measurement that is equal to one eighth of a fluid ounce, or 3.69 milliliters. Both units are commonly used in the United States for measuring small amounts of liquid.