look up any word, like donkey punch:
 
1.
"Survival of the fittest" in its most literal definition. Everyone fends for themselves. If you can't take care of yourself, you get eliminated.
It's a dog eat dog world out there, and they're running out of napkins.
by MAP July 03, 2005
 
2.
Pretty self explanatory..
A twist on Dog fuck dog...
For those who still don't get it... Dog sex.
Sarah: Damn Jill, thats ugly dog eat dog right there