|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a gadget; dingus; thingumbob.|
koan/koh'an/ n. A Zen teaching riddle. Classically, koans are attractive paradoxes to be meditated on; their purpose is to help one to enlightenment by temporarily jamming normal cognitive processing so that something more interesting can happen (this practice is associated with Rinzei Zen Buddhism). Hackers are very fond of the koan form and compose their own koans for humororous and/or enlightening effect. See Some AI Koans, has the X nature, hacker humor.