zip-a-dee-doo-dah

Etymology
From a song in the Disney movie Song of the South, from “O Zip a duden duden duden zip a duden day”, chorus to an old minstrel song “Zip Coon” popularized by George Washington Dixon

Interjection

 * 1) An exclamation of happiness.

Usage notes

 * Due to the saccharine, commercial nature of its usage by Disney, this is often used sarcastically or ironically.

Adjective

 * 1) Characteristic of such a feeling.