1. [ noun ] a small telescope attached to a large telescope to use in setting the line of the larger one
Related terms: telescope collimate
2. [ noun ] (physics,optics) optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens; light rays leave the slit as a parallel beam
Related terms: optical_device spectroscope
Similar spelling:   collimate