I recently happened upon a few new words that I thought were kind of interesting:
I'd heard of kohai and sempai or course (someone who is your junior or senior, respectively), but what if someone is your exact same level? Well, he'd be your dohai.
Public demonstration of a martial art. I've participated in a few, but never knew it had a name!
"Free practice" where one may move around, training with various folks with no formal "lesson." We'll do this in our school periodically, and it's a nice change of pace.
Practice session where two or more dojos get together to share an informal practice. We've always just called these "play days", but now I have something "official" to call it (even if I'm the only one!)
To train through teaching. Ever realize you knew something only when you tried to teach it someone else? Or even learn something entirely new? That's one of the beauties, I think, of budo. Always something to learn, even as the "teacher".
Training by yourself. For the most part, Aikido really requires a partner since it's based primarily on using an attacker's energy against him. But there are other little drills and things a person can do (I'll have to share those another time). Sotai renshu would be training with a partner.
To train by watching. Even when you're injured or not feeling up to snuff, you can (and I have) learn a lot just by watching.
Name board where students names are hung on the wall displaying rank. Lowry Sensei put one of these up in Windsong not too long ago, and it looks pretty good. Windsong is an old dojo, and there are a lot of names, but he made it work. Of course, there's not a lot of room left, so I wonder what will happen when we promote enough dan grades to overflow it?
Quite simply, the foyer, or place where you enter a dojo or place your shoes.