Are there any testing-related methodologies except TDD/BDD? I see a lot of people who practice their own testing approaches (e. g., see Ayende post), but I don't see any formalization for it, no naming for these approaches.
Most test methodologies are integral to the development process they support. For example, in the Waterfall Model, testing follows as feasibility, requirements analysis, system design conformity, Code/Unit testing, Integration/System Testing and finally deployment review/refactoring. It's arguable that this would be called the "Waterfall test" methodology but in effect, that's what it is.
In agile testing, more emphasis is placed on test automation, paired programming (instant test feedback!) and QA within the iterative build cycle.
There are very well defined test methods depending on the software life-cycle needs. Exhaustive lists are available elsewhere but the more common methods include, unit, integration, stress, performance and system testing.
Unlike development processes, however, rigorously defined test methodologies as a standalone practice is lacking. Instead, QA standards are set by a variety of bodies including ISO and CMMi.
Testing is a very general term covering a huge field, so there are a lot of methodologies involved, e.g. risk-based testing, model-based testing or random testing.
It actually makes sense to build a taxonomie, differentiating e.g. manual vs automated testing, white-box vs. black-box testing and the level in the V model (unit, component, system). Here is a mindmap that gives a rough taxonomie.
If you come across a technical term, you will probably find it in this glossary from ISTQB, which is by far the best I know of. ISTQB also offers several syllabus in which you can read up what the terms mean. This foundational syllabus is a good start.