IPA: /ˈmɛdəlˌsʌm.nəs/
KK: /ˈmɛdəlˌsʌm.nəs/
The quality of being overly involved in other people's affairs or business, often in a way that is annoying or unwelcome.
Her meddlesomeness often led her to interfere in her friends' personal lives.
Meddlesomeness → It is formed from "meddle" (from Middle English *meddlen*, meaning to interfere) and "-some" (meaning inclined to or characterized by) combined with "-ness" (meaning the state or quality of). The word describes the quality of being inclined to interfere or intrude in others' affairs.
Think of someone who is 'inclined to interfere' ('-some') in situations that don't concern them, which helps you remember that 'meddlesomeness' refers to the quality of being overly involved in others' matters.