Definition of "backside"

The back side of anything, the part opposite its front, particularly:

1. (UK dialect, euphemistic) an outhouse.  examples

2. (euphemistic) A person's buttocks.  quotations  examples

   Quotations

   • With an arrowe so broad, He shott him into the backe-syde.

     c. 1500, Robin Hood, Bk. ii, Ch. iv, p. 236

   • Our toilet was an outside netty shared between two or three families, where you sat on a hole and hoped the cat wouldn't jump at your backside.

     1992 May 4, The Independent, page 13

3. (obsolete) The back side of a page: a verso.

(figuratively) The reverse or opposite of anything.  quotations  examples

Used other than figuratively or idiomatically: see back,‎ side.  examples

(board sports) Approaching an obstacle backward  examples

Used other than figuratively or idiomatically: see back,‎ side.  examples