Orthonormal tetrad/frame name question

[quasar_4]

This is just a "lingo" question, and maybe it belongs in a relativity/field theory thread instead of here, but does anyone know: is the term "orthonormal tetrad" referring to the same object as an "orthonormal frame"?

The tetrad bit is throwing me off, but I'm pretty sure they're the same. Anyone know?

 

[shoehorn]

Yes, although it's technically incorrect to apply the term "tetrad" in any situation other than with four dimensions, 'tetr-' being the Greek root for "four."