四环素 Traditional form: 四環素 Pinyin (reading): sìhuánsù Definitions: tetracycline Characters: 四 - four 环 - bracelet, ring; to surround, to loop 素 - plain; white; vegetarian; formerly; normally Traditional characters: 四 - four 環 - bracelet, ring; to surround, to loop 素 - plain; white; vegetarian; formerly; normally