Meanings

circle of fifths

Greater China (incl. Hong Kong, Macao, Taiwan and sometimes Singapore)

rhizosphere

beneficiary zone

harm zone

control zone

air defense identification zone

within walking distance

Kansai area

Kantō area

Tokyo area (esp. in ref. to Tokyo, Kanagawa, Saitama and Chiba)

stratoplane (hypothetical type of airplane)

Lebensraum

cryosphere

(within) walking distance

polar circle

surroundings

gnomonic chart

gnomonic projection (in cartography)

Chūkyō metropolitan area (most of Aichi, and parts of Gifu and Mie prefectures; centered around Nagoya)