prefix
Prefix indicating something is subordinate, lower in rank, or of lesser quality. Common in compounds like 亜種 (subspecies) and 亜流 (follower, imitator).
この植物は亜種に分類される。
This plant is classified as a subspecies.
彼は亜流の作家に過ぎない。
He is nothing more than a second-rate writer.
prefix
-ous (low oxidation state); -ite
Chemistry prefix used in compound names to indicate a lower oxidation state, corresponding to English '-ous' or '-ite'. Example: 亜硫酸 (sulfurous acid).
亜硝酸ナトリウムは食品添加物として使われる。
Sodium nitrite is used as a food additive.
noun
Asia (abbr.); Argentina (abbr.); Arabia (abbr.); America (obs. abbr.)
Abbreviation used in ateji country names. 亜 alone can stand for Asia (from 亜細亜), Argentina (亜爾然丁), Arabia (亜剌比亜), and historically America (亜米利加, now obsolete). In modern Japanese, 亜 primarily appears in compounds like 東亜 (East Asia) and 欧亜 (Eurasia).
See also: 亜細亜 (アジア)
「東亜」という言葉は東アジアを指す。
The term 東亜 refers to East Asia.
明治時代には「亜」がアメリカを表す略称として使われた。
In the Meiji era, 亜 was used as an abbreviation for America.
From Chinese 亞 (yà), meaning 'second' or 'inferior'. Used as a prefix in Sino-Japanese compounds. The abbreviation senses derive from ateji usage in country names.