| 1. | with the upper part undermost. |
| 2. | in or into complete disorder; topsy-turvy: The burglars turned the house upside down. |
| upside down adv.
[Alteration of Middle English up so doun, up as if down : up, up; see up + so, as if; see so1 + doun, down; see down1.] up'side-down' (ŭp'sīd-doun') adj. |