The word "mitre" refers to a tall pointed hat worn by certain religious leaders, such as bishops or abbots, as a symbol of their authority in some Christian denominations. Full definition
MITRE Corporation is applying Semantic Web tool kits to help the U.S. military interpret rules of engagement for convoy movements. (scientificamerican.com)
The other, neater, method is to use mitre joins. (idealhome.co.uk)
Then Greg shows an installation in a factory, with walls laid on their sides, with a big mitre box cutter to make the cutting of batts perfectly square. (treehugger.com)