preinvasion

adjective

pre·​in·​va·​sion ˌprē-in-ˈvā-zhən 

variants or pre-invasion

: taking place in the period immediately preceding a military invasion

preinvasion bombardment

London in that preinvasion spring seemed full of color and gaiety. Uniforms of different nations abounded, and the air was charged with excitement and a tense anticipation.

—Louis Auchincloss

Word History

First Known Use

1926, in the meaning defined above