血清素 Traditional form: 血清素 Pinyin (reading): xuèqīngsù Definitions: serotonin Characters: 血 - blood 清 - clean, pure; clear, distinct; peaceful 素 - plain; white; vegetarian; formerly; normally Traditional characters: 血 - blood 清 - clean, pure; clear, distinct; peaceful 素 - plain; white; vegetarian; formerly; normally