Stuck a feather in his cap / And called it macaroni - "Macaroni" refers to Italian and French fashion, which the colonist thought he could approximate by sticking a feather in his outdated or bizarre, by European standards, cap.
2. Вид наказания (вымазать в смоле и вывалять в перьях). Сейчас это называется tarred and feathered.