IPA: /ˌɪnədˈvɜːtəns/
KK: /ˌɪnədˈvɜːrtəns/
A mistake made because someone was not paying attention or did not mean to do something.
The error was due to his inadvertence during the meeting.
Inadvertence → It is formed from "in-" (meaning not) and "advertence" (from Latin "advertere", meaning to turn towards). The word refers to a lack of attention or oversight, essentially meaning not turning one's attention to something.
Think of 'not' paying attention ('in-') and 'turning towards' ('advertence') — that's why inadvertence means a lack of attention.