素数: prime number (natural number)

飛鼠: bat (small flying mammal)

熊襲: A geographical region in the southern area of Kyūshū; an ancient ethnic group living in the Kumaso region.

鼠蹊管: inguinal canal

祖型: archetype / 素馨: Spanish jasmine / 粗景, 麁景: gift / 鼠蹊, 鼠径: groin

ヨウ素, 沃素: iodine

ヒ素, 砒素: arsenic

生長素: (botany) auxin

安息日: Sabbath

単組: abbreviation of 単位組合 (tan'i kumiai): a unit association, the smallest sub-group within a labor union / 炭疽: anthrax (the disease) / 炭素: carbon (chemical element)