Definitions for upside-down
Random House Webster's College Dictionary
with the upper part undermost.
in or into complete disorder; topsy-turvy:
to turn the house upside down.
Origin of upside down:
1300–50; ME upsedoun, earlier up so doun
being in such a position that top and bottom are reversed
"a quotation mark is sometimes called an inverted comma"; "an upside-down cake"
in an inverted manner
"the box was lying on the floor upside down"