A phrase coined to be an abbreviation of "Let's dip to the loin." Dip meaning to go, Loin being the tenderloin neighborhood in San Francisco (a very drug and depravity infested area.) It has taken on just about every other meaning possible, but typically it just means "let's go get fucked up." Other Examples: The loins of dippage, the dipartment of homeloin security etc. This is a locally used term in P-town (Pacifica) California among drug addict kids. fashadidayadidadoh.
"Ey, if I was a Jew in Auschwitz... I'd dip loin dip."
Doctor: "It's time to administer your anal treatment"