IPA: /ˌpriːˈɒkjʊpaɪd/
KK: /priˈɑkjupaid/
Being so focused on something that you are not aware of what is happening around you.
She seemed preoccupied during the meeting and didn't notice when her name was called.
Preoccupied → It is formed from "pre-" (meaning before) and "occupare" (meaning to seize or take). The word describes a state of being seized or taken by thoughts or concerns before one is able to focus on other matters.
Think of being 'seized' ('occupare') by thoughts 'before' ('pre-') you can focus on what's happening around you.