like ineffable. Sure, it's a word the average person would rarely use in conversation. You don't hear people say, "Wow, that touchdown pass was... ineffable."
Because ineffable literally means "incapable of being expressed in words," according to my favorite online dictionary, www.m-w.com.
It's been stuck in my head recently due to its usage in a running faith-based debate on Andrew Sullivan's blog at www.theatlantic.com. And when it comes to discussing God, ineffable feels appropriate. Frankly, I'm hoping to encounter many instances throughout my life that are... ineffable.