also: りっかい
land and sea
Refers to both land and sea as a pair, often used in contexts like transportation, geography, or military operations.
The land and sea transportation network is well developed.
army and navy
Used to refer to both the army and navy together, often in historical or military contexts. Cross-references 陸軍 and 海軍.
Both the army and navy conducted exercises.
Securing safe transport routes was urgently needed, whether by land or sea.