As I browse through the site, I find a lot of terms that many developers just starting out (and even some advanced developers) may be unfamiliar with.
It would be great if people could post here with a term and definition that might be unknown to beginners or those from different programming backgrounds.
Some not-so-common terms I've seen are 'auto boxing', 'tuples', 'orthogonal code', 'domain driven design', 'test driven development', etc.
Code snippets would also be helpful where applicable..
Someone may have beat us to it ;)
http://en.wikipedia.org/wiki/Boxing_%28Computer_science%29#Boxing
thats the correct link for boxing as related to computer science :D
Better yet, a site domain dictionary, containing a definition (over time) for every programming term on Stackoverflow, with the definition itself modded according to the Wiki-like aspects Atwood and others have been discussing.
There are coding dictionaries out there but they're all either a) crap or b) not extensible or editable in a collaborative way.
Right now if I come across an unfamiliar programming term or acronym my first stop is Google, followed by Wiki, followed by one of the many dedicated dictionaries. No reason why Stackoverflow shouldn't be on that list.
The c2 Wiki kicks butt. Great combination of concise definitions and examples, plus discussions that break it down when there are different interpretations.
It may actually be helpful to go around adding the tag 'glossary' to specific questions (I recently saw one about Expressions vs. Statements, for instance).