Invasion
Invasion (from Latin), 1) Attack; 2) Hostile Incursion; hence war of invasion, war of aggression by sudden incursion into enemy territory.
Source: Pierer’s Universal-Lexikon 4. Auflage 1857–1865
Invasion (Latin), a hostile incursion into a foreign country, especially one not intended for permanent conquest but only for a temporary purpose.
Source: Brockhaus’ Kleines Konversations-Lexikon, 5. Auflage 1911
Invasion (Latin), incursion, especially a hostile incursion into foreign territory; invasion war, a war of aggression involving actual penetration into the enemy‘s land. Cf. conquest and occupation.
Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909