Definition of non-intervener in US English:

non-intervener

noun

  • A person who does not intervene; specifically an advocate of political non-intervention.

Origin

1930s; earliest use found in Alan Patrick Herbert (1890–1971), author and politician. From non- + intervener, after non-intervene.

Pronunciation

non-intervener

/ˌnɒnɪntəˈviːnə/