Definition of moenie in US English:

moenie

(also moeni, mooni)

verb

informal
  • no object And as an auxiliary with bare infinitive: don't; (you) mustn't. Frequently used humorously in phrase "moenie panic (also worry) (nie)": don't panic, don't worry.

Origin

Early 20th century; earliest use found in Charles Pettman (b. 1851). From Afrikaans moenie —— (nie) must not, do not ——, shortened from Dutch moet niet from moet + niet.

Pronunciation

moenie

/ˈmʊni/