upside down

adverb

1. with the upper part undermost.

2. in or into complete disorder; topsy-turvy.

   The burglars turned the house upside down.

upside down

adjective

1. (usually postpositive; upside-down when prenominal) turned over completely; inverted

2. informal,  (upside-down when prenominal) confused; muddled; topsy-turvy

   an upside-down world

adverb

1. in an inverted fashion

2. in a chaotic or crazy manner

Other Word Forms

• upside-down adjective
• upside-downness noun

Word History and Origins

Origin of upside down¹

1300–50; re-formation ( upside ) of Middle English upsedoun, earlier up so doun ( up, so ¹, down ¹; sense of so obscure)

Word History and Origins

Origin of upside down¹

C16: variant, by folk etymology, of earlier upsodown