Sensei- 'One who has gone before', an instructor who runs a school. Literally one who has already done everything a new student will be asked to do.
Renshi- 'instructor who polishes', an area director who is the 'muscle' of an organization. This person maintains the high ethical standards of an organization and enforces that standard. They are first to stand up to any challenge of authenticity and upholds honor in the organization.
Karate- 'Empty hand'. There are two types, DO and JITSU. Karate-do is the type of art that encourages awareness and change in a person through training in primarily striking and kata, (pre-arranged forms). Karate-Jitsu means a rounded, complete art incorporating striking and grappling. Pioneered by Jon Bluming of Holland.
Jujitsu/Jiujitsu- 'The gentle art'. An art that encompasses ground self defense through falls, rolls, holds, chokes and breaking techniques.
Combatives- The way of using everything for self defense, especially short, brutal self defense techniques and weapons. Rooted in WWII army combatives techniques.
Krav Maga- 'Contact combat' in Hebrew. A complete defensive tactics system that emphasizes pure self defense, there is no sport aspect to Krav Maga.
Dojo- 'The place for learning the way'. Any place where you endeavor in the martial arts. A building, a basement or even your backyard.
Osu- 'To push or suffer'. In training we must suffer discomfort and sometimes pain to realize true change in our bodies, (working out), or our mindset, (self defense scenarios).
Goshin jitsu- 'Art of defending'. Training in the defense of one's self, family/friends or even home or business.