An experiment...

[Shagbeard]

Sure we see the Dude say he abides, but what things should not be let to abide?  In your own opinion what can not be abided.

[Hominid]

Unabidedness.  Intolerance of the Eagles.  $1,000 blow jobs.  Aggression.  Expensive human ash containers.  Uninvited compeers.  Nihilistic johnson cutters. 

Shall I continue?  ;-)

[Jefftos]

Rug Pee'rs?

[DigitalBuddha]

Hey, this is a private residence, man!

https://www.youtube.com/watch?v=JK6JojS2A2Q

[CyberDude]

another toe.

[DigitalBuddha]

I'm the dude, so that's what you call me...

[Shagbeard]

So only quotes hmmm

[Hominid]

We can be an obtuse bunch...


Vagina.

[BikerDude]

It's part of the enigma of the Dude.
On one hand we are told that he is one of the authors of the Port Huron statement.
Something of a manifesto for the SDS full of strong principles.
http://coursesa.matrix.msu.edu/~hst306/documents/huron.html
This would suggest that the Dude is a person more driven by Ideals than the average person, yet the Dude we see is remarkably slack in his adherence to any real ethos. (Except maybe the distillation of his sensibilities that we lovingly call Dudeism).
Perhaps that is the key to the term Abide. Although we know the Dude is, at least theoretically, driven by high ideals, he doesn't typically take a stand for them.
He abides.