"Ground invasion" refers to the act of sending military forces or troops onto enemy territory to engage in combat or seize control of that area rather than using weapons from the air or sea. Full definition
Israel's diplomats are assuring western countries that it has no intention of mounting a full ground invasion of the Gaza Strip. (politics.co.uk)
It is set in a world that has been virtually decimated by four waves of violent extra-terrestrial attacks; the first of which saw power supplies shut down, the second unleashed a deadly virus, the third saw floods wipe out large areas and the fourth was a widespread ground invasion in which the marauding aliens began to take human hosts. (awfj.org)
Late that summer, Hitler and the German Luftwaffe turned their attention to England, with the Nazi dictator aiming to use his air forces to soften up Great Britain for an eventual ground invasion — codenamed Operation Sea Lion. (businessinsider.com)