Panta, here is a brief explanation of at least some of the terms Hengest listed. Feel free to correct or add to any of them:
Tessenjutsu - This is use of an iron warfan, used like a truncheon for in-fighting on the battlefield. I've heard of them being made with mirrored surfaces that could reflect light into the eyes of your enemy, be used as a shield against thrown objects, and can be opened suddenly as a distraction. You can also beat the guy silly with it.
Juttejutsu - A truncheon with a single prong on the side, which can be used to catch swords and disarm the opponent. It can also be used to aid small-joint manipulation and puncture kyusho. Used by police as a non-lethal means to detain unruly samurai, but also used on the battlefield in grappling (and to break open helmets).
Kusarijutsu - Chain weapons... flexibility allows dynamic range, unpredictable movement, yet unlike a rope can be used directly against bladed weapons.
Kamajutsu - The short sickle weapon, used alone or sometimes attached to a chain (kusari-gama, the "k" becomes a "g" in conjunction with another word).
Kusaribojutsu - I'm assuming this is a chain weapon hidden inside a cane, or a sectional staff weapon of some kind.
Tekkenjutsu - One of the few forms of digital combat that cannot be dominated by sheer button-mashing. Naw, I actually don't know what this is.
Koppojutsu - A typically unarmed method (though the principles apply to weapons use), my favorite translation is "breaking the structure." Focuses on percussive manipulation of the opponent's skeletal alignment to lock up the body, destroy joints, and expose vital points. Hatsumi soke has also referred to "koppo" as simply meaning "knack," like to have skill at something, so it could just be a way of referfing to knowing when and where to hit someone.
Kosshijutsu - Often interpreted as bone-finger art and previously known as shito-jutsu this style makes frequent use of finger drives (shito-ken) to attack the nervous system and organs. It also means backbone, which can refer to the use of rotating the spine to generate power, the way its techniques affect the opponent's spine (twisting it up to take his balance and create tension for vital strikes), and sometimes to figuratively refer to it as the "backbone of martial arts."
Kyushojutsu - Attacks to weak points, often based on accu-points from chinese medicince which are often related to the nervous and circulatory systems. Kyusho also include organs, joints, weak bones, arteries, and so forth, usually attacked through surface areas that do not accumulate muscle or fat tissue.
Nageyarijutsu - throwing spears, I gather.
Hojutsu - Use of the rope in combat, for capturing and restraining. I heard a story of Hatsumi tying up Shiraisi-sensei and walking away, where the poor shihan was still standing (barely) but any movement on his part (including falling) would either choke him or break one of several small joints. Being Shiraisi, he was of course grinning like a fool the whole time
Bajutsu - Horsemanship, for riding in armor and fighting from horseback with various weapons.
Kyujutsu - Archery... only a couple koryu kyujutsu exist today, most were homogonized into the gendai art of kyudo.