fluidramAvoid the misspellings fluid dram and fluiddram. A measure of capacity: 1/8 of a fluidounce; a teaspoonful. The imperial fluidrachm contains 54.8 grains of distilled water, and equals 3.55 mL; the U.S. fluidrachm contains 57.1 grains of distilled water and equals 3.70 mL.