Top definition
Someone who is extremely picky about all things sustainable. Will call other people on their unsustainable behaviour. Combination of sustainable and anal.
Mike is so sustainal, he criticized me for throwing my banana peel in the wrong bin.

Stop being sustainal, Mike, get a life!
by R-NO April 27, 2010
Get the mug
Get a Sustainal mug for your bunkmate Larisa.