The defintion that makes the most sense to me is:
http://onlinedictionary.datasegment.com/word/nevertheless
nevertheless - WordNet (r) 2.1 (2005) :

nevertheless
adv 1: despite anything to the contrary (usually following a
concession); "although I'm a little afraid, however I'd
like to try it"; "while we disliked each other,
nevertheless we agreed"; "he was a stern yet fair
master"; "granted that it is dangerous, all the same I
still want to go" [syn: however, nevertheless,
withal, still, yet, all the same, even so,
nonetheless, notwithstanding]

The [/concession] aspect is the part of the definition that makes the most sense to me. Seems that many idioms get taken for granted over the years. I appreciated the question and the opportunity to think about it. Thanks Janis and everyone for all the answers.

BTW, I'm very new to the world of code, irregardless and nevertheless, I'm going to give it a try here and hope you'll forgive me for experimenting.