pre ‧ oc ‧ cu ‧ pa ‧ tion /priːˌɒkjəˈpeɪʃ ə n, priːˌɒkjʊˈpeɪʃ ə n $ -ˌɑːk-/ BrE AmE noun
1 . [singular, uncountable] when someone thinks or worries about something a lot, with the result that they do not pay attention to other things
preoccupation with
the current preoccupation with sex and scandal
The management’s preoccupation with costs and profits resulted in a drop in quality and customer service.
2 . [countable] something that you give all your attention to
main/chief/central etc preoccupation
Their main preoccupation was how to feed their families.