Meaning of circumferentor

cir•cum•fer•en•tor

Pronunciation: (sur-kum'fu-ren"tur), [key]
— n. Survey.
  1. an alidade equipped with a compass and two diametrically opposed vertical arms with slits for sighting through.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.