look up any word, like the eiffel tower:
 
1.
A complementary girlfriend "on the side", or "bootycall" which delivers sexual gratification at times when the main relationship seems lacking.
My girl won't put out these days. Good thing I have a sideride!
by Sam K. June 02, 2004
 
2.
n. A guy you're having illicit sex with out side of your current relationship. The other man.
My guy would go crazy if he caught me shoving with my side ride...
by Amy_1981 August 12, 2006