noun

• (martial arts) A training facility, usually led by one or more sensei; a hall or room used for such training.
  "I was to be there [Helsinki, Finland] for over two weeks; and because a hotel room affords a rather awkward place of practice, I went looking for a dojo. Finally after hearing rumors of dojos from various citizens I turned to the equivalent of Helsinki's Yellow Pages. There I found listed, under Meido-Kan, the name of one Kare K. Käyhkö."
• (by extension) A room or other facility used for other activities, such as meditation or software development.
  "Earlier dojos were known as homebrew clubs. [...] In Silicon Valley, a dojo is defined as a do-ocracy where people come together based on shared interests and passions, such as coding and robotics. [...] David Crawley, a semiconductor physicist and founder of Hacker Dojo Robotics, shared with me that it had been a passion of his to pull robotics hobbyists together with 12 challenges in mind: drive around three cones, deliver a pizza from the front door of the dojo to a predetermined location inside, [...]"
• (sumo) Synonym of dohyo (“the ring in which a sumo wrestling match is held”).
  "In this class of truck it’s all about torque, and the Hilux has that in spades. [...] Its traction control stamps the ground with the immovable authority of a sumo wrestler entering the dojo."