noun, plural abacuses, abaci. [ab-uh-sahy, -kahy, uh-bak-ahy] /ËÃ¦b ÉËsaÉª, -ËkaÉª, ÉËbÃ¦k aÉª/ (Show IPA) 1. a device for making arithmetic calculations, consisting of a frame set with rods on which balls or beads are moved. 2. Architecture. a slab forming the top of the capital of a column. Origin of abacus.
Sulfate is any salt or ester made up of sulphuric acid. Sulfide is used to describe any of three types of chemical compounds that contain sulfur. Sulfite is sulfur dioxide, or SO2.
Sulfa drugs (also called sulphur drugs or sulfonamide-containing drugs) is an imprecise term that generally refers to drugs that contain a sulfonamide functional group in their chemical structure. These drugs have a variety of uses and can be classified into antibiotics and non-antibiotic drugs.