This is the 15275th most frequent Russian word.
послевоенная
"Postwar."
The word 'послевоенная' functions as an adjective describing 'жизнь' (life), indicating the time period after the war.
Послевоенная жизнь в деревне была полна трудностей.
Post-war life in the village was full of hardships.
Here, 'послевоенная' serves as an adjective qualifying 'экономика' (economy), specifying the economic conditions following the war.
Послевоенная экономика страны стремительно росла.
The post-war economy of the country grew rapidly.
'Послевоенные' as a plural form of the adjective relates to 'годы' (years), highlighting the timeframe after the war.