Japanese Terminology used in the dojo

Commands, greetings, etc
hajime begin / start
kiai yell
kosa switch feet
mawatte turn around
mokuso meditate - compose yourself
na-otte recover (rarely used; most people say `yame')
osu! mean `yes' or `OK' in karate clubs.
rei bow
seiza sit down
yame stop
yasume have a rest
yoh-i Come to attention

Training methods and practical matters
dan graduate. `Dan grades' are black-belt grades
dojo training hall (literally `place of the way')
gohon kumite five-step sparring
ippon kumite one-step sparring
jiyuu kumite free sparring
kata preset sequences of moves
kihon fundamentals (the practice of stances, blows, blocks, etc)
gi (also `dogi' or `do-gi' or `karate-gi') uniform
kime focus (literally `decision' or `commitment')
kumite sparring
kyu student. `Kyu grades' are pre-black-belt grades
kyoshi teacher (neutral term, not deferential like `sensei')
obi belt
sanbon kumite three-step sparring
sempai mentor, senior student
shihan honorific term meaning `expert'; loosely translated as `master' 
shomen founder, or front. Literally `sho-men', `first head'. Now only used in ritualistic formulations like `shomen no rei' -- `we bow to the founder', which could also be translated as `we bow to the front'.

Stance and posture
dachi stance
gamae posture
hachiji-dachi open-leg stance
hanmi-gamae half-facing posture
heiko-dachi parallel-leg stance
heisoku-dachi formal attention stance
kokutsu-dachi back stance
mosubi-dachi informal attention stance
kiba-dachi `horse riding' stance
neko-ashi-dachi cat stance
renoji-dachi `L' stance
shizentai natural stance
teidi-dachi `T' stance
yoko-gamae side-facing posture
yoi attention stance; rather informal way of saying `shizentai'
zenkutsu-dachi Front stance

Blocks and defenses
age uke rising block
gedan barai downward block
juuji uke `X' block or cross block
(soto) ude uke outside forearm block
shuto (uke) knife-hand block
uchi (ude) uke inside forearm block
uke block

Hand and arm strikes
choku tsuki straight punch
enpi uchi elbow strike
gyaku tsuki reverse punch
kizami jab
oi tsuki step or lunge punch
tsuki punch
nukite uchi spear-hand strike
tettsui hammer fist strike
uchi strike inside forearm block.
uraken uchi back-fist strike
ura tsuki uppercut

Foot and leg strikes
geri kick
ashi barai foot sweep
mae geri front kick
mawashi geri roundhouse kick
mikazuki geri crescent kick, also called `hook kick' or `drop kick'
ushiro geri back kick
yoko (geri) kokomi side kick with `thrusting' action
yoko (geri) keage side kick with `snapping' action

Anatomical and targeting
ashi foot or lower leg
chuudan mid-level (typically aimed at the solar plexus)
enpi elbow
gedan low level (anything below the belt)
hara see `tanden'
jodan upper level (typically aimed at the head)
haito `ridge hand'; the edge of the hand with the thumb
hidari left (as in left-hand). Normally used in descriptions of stances
migi right (as in right-hand). Normally used in descriptions of stances
seiken `forefist'. Since most hand strikes are with the forefist, the term is not used all that much
shotei `palm heel'; the palm of the hand when the fingers are drawn back
sokuto `knife foot'; foot position for side kicks. The term is also used in some clubs to mean the kick itself
shuto `knife hand'; also used as abbreviation for `shuto uke' -- knife hand block
tanden the mystic `centre of gravity' of the body; I favor the translation `belly'
uraken `back fist'. Usually used in `uraken uchi' which is a blow delivered with the back of the fist rather than the knuckles and forefingers.

Training methods and practical matters
dan graduate. `Dan grades' are black-belt grades
dojo training hall (literally `place of the way')
gohon kumite five-step sparring
ippon kumite one-step sparring
jiyuu kumite free sparring
kata preset sequences of moves
kihon fundamentals (the practice of stances, blows, blocks, etc)
gi (also `dogi' or `do-gi' or `karate-gi') uniform
kime focus (literally `decision' or `commitment')
kumite sparring
kyu student. `Kyu grades' are pre-black-belt grades
kyoshi teacher (neutral term, not deferential like `sensei')
obi belt
sanbon kumite three-step sparring
sempai mentor, senior student
shihan honorific term meaning `expert'; loosely translated as `master'
shomen founder, or front. Literally `sho-men', `first head'. Now only used in ritualistic formulations like `shomen no rei' -- `we bow to the founder', which could also be translated as `we bow to the front'.

Commands, greetings, etc
hajime begin / start
kiai yell
kosa switch feet
mawatte turn around. Normally used to mean `face the opposite direction'
mokuso meditate; not usually in the zen sense, but rather in the `compose yourself' sense
na-otte recover (rarely used; most people say `yame' instead)
osu! (usually mispronounced `oss' or `oos' in the UK) Difficult to translate accurately, the term is often used to mean `yes' or `OK' in karate clubs.
rei bow
seiza sit down
yame stop (sometimes interpreted as `relax'; a better word for relax is `yasume')
yasume have a rest (rarely used; most people say `yame' instead)
yoh-i (usually pronounced in the UK like a long-drawn-out `yoi') Come to attention; assume the yoi stance

Pronunciation
Although Japanese words can be transliterated into English symbols in a variety of different ways, certain standards are adopted by most Japanese writers. This section describes the most elementary of these standards.

On the whole, don't expect members of your club to pronounce Japanese words even close to the way that a Japanese person would. Most English people don't have the time to learn Japanese just so they can pronounce karate words properly, so they tend to get pronounced as English words would be. Thus `gyaku' often gets pronounced `gee-akoo' which is miles away from the `proper' pronunciation. In practice you will have to follow the pronunciation standards of your club if you want to be understood, even if you have to grit your teeth to do so.

Single vowels are usually pronounced short. So the letter `a' is like a short version of the `ar' in `cart'. `e' as in `ted', `u' as the `oo' in `foot' (not in `boot'). `o' as in `hot'. `i' as in `sip' but with a hint of `ee'.
Short vowels are often under-emphasized. When a word ends in a short vowel, the vowel is shortened still futher and cut off sharply. So `osu' is `os' with a very short, sharp `u' on the end. Most non-Japanese people can't pronounce this so, for example, `osu' comes out as `oss'. `tsuki' should be `ts(u)k(i)', that is, somewhere between `tsuki' and `tsk'.
 
When double vowels are written (as in, for example, `jiin'), they are simply sounded for longer, not pronounced as different sounds. Doubled consonants are usually sounded with a short pause between the letters (so `tettsui' is `tet-tsui', not `tetzui').

Apart from the doubled vowels, there are other long vowel sounds usually written as two different vowels. So: `ae' is pronounced like the `ay' in `day'; `ai' like the `y' in `style'.

Consonants are normally sounded as they would be in English. There are a few exceptions. The letter written `r' is pronounced a bit like a `d' in the middle of a word, and a bit like `l' at the begining (rhere is no real `r' sound in Japanese). The `ts' sound in `tsuki' is shortened to a `z' when not sounded alone. `g' in the middle of a word is often `ng', so `migi' -- right -- is pronounced `ming(i)' (where, strictly, the last `i' is shortened).

The letter `y' can be vowel-like as well as consonantal, as in English. To emphasise the consonantal pronunciation, some words are written with `gy' instead of `y'; the `g' is not pronounced, but merely indicates that `y' is not to take any vowel sound. Thus `gyaku' -- opposite, reverse -- is `yak(u)' not `ee-ak(u)'.