pre ‧ oc ‧ cu ‧ py /priːˈɒkjəpaɪ, priːˈɒkjʊpaɪ $ -ˈɑːk-/ BrE AmE verb ( past tense and past participle preoccupied , present participle preoccupying , third person singular preoccupies ) [transitive]
formal if something preoccupies someone, they think or worry about it a lot