trisector

Noun

trisector (plural trisectors)

1. A line or curve that trisects something.
   • Coordinate term: bisector
2. (informal) Someone who believes to have found a way to construct an angle one-third the size of an arbitrary angle using only an unmarked straightedge and compass (this is known to be impossible; see Angle trisection § Proof of impossibility on WikipediaWikipedia ).
   • A trisector is a person who has, he thinks, succeeded in dividing any angle into three equal parts using straightedge and compass alone. He comes when he sends you his trisection in the mail and asks your opinion, or (worse) calls you to discuss his work, or (worse still) shows up in person. You...1983, Underwood Dudley, “What To Do When the Trisector Comes”, in The Mathematical Intelligencer, volume 5, number 1, New York, N.Y.: Springer-Verlag New York, →ISSN, →OCLC, page 20, column 1