Invade/ɪnˈveɪd/ Definition 1 of 4Pro Tip 1/3Hostile Action Used to describe aggressive military actions like an attack or takeover. During World War II, many countries experienced invasions. Pro Tip 2/3Conquest Implied Suggests an attempt to control or dominate a place. Ancient Rome was known to invade territories to expand its empire. Pro Tip 3/3Historical Usage Commonly found in historical or wartime contexts. The history book detailed how Vikings invaded European shores.