Before I start writing down random terms, I'll try to introduce you to what sushi really is in a few sentences. Sushi is rice drenched in vinegar, which was initially only used for the transportation of fish on the islands of what now is Japan, China, Korea and Taiwan. It is only afterwards that it was regarded as a delicacy. There are many kinds of serving you sushi, a lot of those involve (raw) fish, but others are purely vegetarian. So now you're ready for reading the ten terms I selected:
Gohan: Rice
The main basis for sushi is rice, short grain sticky rice.
Sushi-Su: Vinegar
Basically sushi is just the rice and the vinegar (white vinegar, with salt and sugar).
Nori: Seaweed
Green "paper" that is used in a lot of styles of sushi.
Sashimi: Sliced Raw Fish, Squid, Octopus, Whale...
Basically if you hear sashimi it's sliced and raw. It is not always eaten on sushi, you can just order sashimi.
Wasabi: Green Root Mustard
Sometimes it's already included in the sushi, sometimes you can choose to add it yourself either to your soy-sauce or just plainly put it on your sushi.
Wasabi-Nushi
For a person who doesn't like wasabi, the term can be handy in a restaurant.
Kaiten-Zushi: Rotating Sushi Restaurant
You sit down and take the dish you want from the rotating conveyor. There are different coloured plates which each have their price. Some plates may have a special logo on them, they are free plates, if you are lucky and grab one, everyone will cheer for you. This depends on the restaurant, but it is common. Although you're supposed to take the dishes from the conveyor, you can also order dishes (without wasabi or special dishes for example)
Hashi: Chopsticks
In Tokyo (Kanto area) you should eat your sushi without chopsticks, but in Kyoto (Kansai area) people may give you chopsticks. If you know how to use hashi, then you may try to use them.
Shoyu: Soy Sauce
Soy sauce is for whatever fish, sea creature is lying on your sushi, if you can avoid it, don't dip your rice into the sauce, try to dip the fish part in the sushi.
Gari: Pickled Ginger
Mainly pink, but can be found in all colours. It's sometimes served with sushi either you like it or you don't, don't try the whole heap the first time.
With this list you should survive a business dinner in a sushi bar/kaiten-zushi/sushi restaurant. Itadakimasu! (let's eat).
