Everyone agrees the three letter acronym starts with Test. After that we have:
Since development is obviously a broader term hence the need for the other two options centering around the word design. Since developers pretty much uniformly hate testing versus designing and writing code adding the word design attempts to point out the benefits of writing tests first on software design. Then there’s a bit more clarity to Test First versus Test Driven. I actually think Test First Design is probably the clearest, but I tend to stick to Test Driven Development or just TDD myself.