[かい, kai](n) (1) (biological) kingdom; (2) erathem (rock layer corresponding to the era in which it was deposited); (3) partition of land; (suf) (4) the world of (some category)#1313[Add to Longdo]
[こっきょう(P);くにざかい;こっかい(国界;国堺)(ok), kokkyou (P); kunizakai ; kokkai ( kuni kai ; kuni sakai )(ok)](n, adj-no) national border; provincial border; (P)#3982[Add to Longdo]
[ケイーティーきょうかい(K−T境界);ケイティーきょうかい(KT境界), kei-tei-kyoukai ( K-T kyoukai ); keitei-kyoukai ( KT kyoukai )](n) K-T boundary (between the Cretaceous Period and the Tertiary Period)[Add to Longdo]
[ロシュげんかい(ロシュ限界);ロッシュげんかい(ロッシュ限界), roshu genkai ( roshu genkai ); rosshu genkai ( rosshu genkai )](n) Roche limit; Roche's limit (closest that a natural satellite can come to the center of a planet without disintegrating due to tidal forces)[Add to Longdo]