"For the bored noder, overall needs a new WU…I'm talking about the 'all things considered' overall…"
For some non-obsolete meanings:
As an adjective, overall can be defined as taking everything into account (but not, necessarily, all-inclusive).
As an adverb, overall can be defined as in all parts; taken as a whole.
Having considered all things, it would be remiss of me if I failed to mention that one overall plus one overall does not equal two overalls, or even one pair of overalls. This could have something to do with the fact adjectives and adjectives aren't constants and variables. That or English and Mathematics are separate disciplines, overall.