The word "most invaded" can be replaced by various synonyms such as "besieged," "overrun," "captured repeatedly," and "conquered repeatedly." Other suitable options include "assaulted," "invaded incessantly," and "stormed frequently." These words imply that a place or nation has been attacked or taken over multiple times, indicating a history of war and turmoil. Additionally, one can use "most violated," "most trespassed," "most infiltrated," and "most encroached" as synonyms for "most invaded." These terms evoke a similar sense of violation and invasion, highlighting the constant threats that the affected area or society has had to face over the years.