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.
Quick Answer. Sulfa is a type of pharmaceutical drug that contain sulfonamides. Sulfonamides are compounds that contain nitrogen, hydrogen, oxygen and the sulfur they take their name from. Sulfur is a chemical that is extremely small and unlikely to cause allergic reactions on its own, unlike sulfonamides. Continue Reading.
Sulfa drugs are based on or derived from the chemical sulfonamide which contains a sulfur dioxide group in each molecule. In my body, about 15% of the drug is digested to release sulfur dioxide and cause a headache.