(taxonomy) subfamily

in class

a visit by a student's guardians to observe the class

rank / follow / sub- prefix

(chemistry) indicates a lower oxidation number: -ous

ranking next, coming after, sub- / Short for アジア／亜細亜 (Ajia, “Asia (a continent)”). / (obsolete) Short for アメリカ／亜米利加 (Amerika): America, the United States / Alternative spelling of 堊 (a): white earth

a female given name

transplant rejection / allergic reaction

chain reaction (series of events) / chain reaction (type of nuclear reaction)

an overreaction