This page should be your first port of call for the meaning of any Jitsu or martial-arts terms used in my posts. The majority of the non-English terms come from Japanese.
These translations are 1. approximate at best, given the differences in form and style between English and Japanese, and 2. based on my own best knowledge. If there's anything I've obviously got wrong or missed out, feel free to correct me.
Dojo: (n.) [Literally "Place of the way"] The room/area in which martial arts training is carried out. Also, by extension, the group that trains in that area.
Rei: (vi.) [pron. "Ray"] To bow as a mark of respect, and to signal one's preparedness to train. Also, as a noun, the bow itself. Jitsuka rei when entering or exiting the dojo, stepping on or off of the training mat, or when beginning or ending a competition, demonstration, or training segment.
Sensei: (n.) [pron. "Sen-say", lit. "born before"] A Japanese title of respect, attributed to lawyers, doctors, accomplished artists, and other respected professions. In a martial arts context, the teacher who leads a dojo is always addressed as "Sensei" while in the dojo.
Tori: (n.) [pron. "toh-ree"] The training partner who performs the technique. See uke.
Uke: (n.) [pron. "uh-key"] The uke, or "receiver", is the training partner who has a technique performed on them.
(More to come, promise!)